Java client documentation

This documentation is for developers interested in using the GOV.UK Notify Java client to send emails, text messages or letters.

Set up the client

Install the client

The notifications-java-client deploys to Maven Central.

Go to the GOV.UK Notify Java client page on Maven Central [external link]:

Select the most recent version.
Copy the dependency configuration snippet for your build tool.

Refer to the client changelog for the version number and the latest updates.

Create a new instance of the client

Add this code to your application:

import uk.gov.service.notify.NotificationClient;
NotificationClient client = new NotificationClient(apiKey);

To get an API key, sign in to GOV.UK Notify and go to the API integration page. You can find more information in the API keys section of this documentation.

If you use a proxy you can pass it into the NotificationClient constructor.

import uk.gov.service.notify.NotificationClient;
NotificationClient client = new NotificationClient(apiKey, proxy);

Send a message

You can use GOV.UK Notify to send text messages, emails and letters.

Send a text message

Method

SendSmsResponse response = client.sendSms(
    templateId,
    phoneNumber,
    personalisation,
    reference,
    smsSenderId
);

Arguments

templateId (required)

To find the template ID:

Sign in to GOV.UK Notify.
Go to the Templates page and select the relevant template.
Select Copy template ID to clipboard.

For example:

String templateId="f33517ff-2a88-4f6e-b855-c550268ce08a";

phoneNumber (required)

The phone number of the recipient of the text message. This number can be a UK or international number.

String phoneNumber="+447900900123";

personalisation (required)

If a template has placeholder fields for personalised information such as name or reference number, you must provide their values in a map. For example:

Map<String, Object> personalisation = new HashMap<>();
personalisation.put("first_name", "Amala");
personalisation.put("application_date", "2018-01-01");
personalisation.put("list", listOfItems); // Will appear as a comma separated list in the message

If a template does not have any placeholder fields for personalised information, you must pass in an empty map or null.

reference (required)

A unique identifier you create. This reference identifies a single unique notification or a batch of notifications. It must not contain any personal information such as name or postal address. If you do not have a reference, you must pass in an empty string or null.

String reference='STRING';

smsSenderId (optional)

A unique identifier of the sender of the text message notification.

To find the text message sender:

Sign in to GOV.UK Notify.
Go to the Settings page.
In the Text Messages section, select Manage on the Text Message sender row.

You can then either:

copy the sender ID that you want to use and paste it into the method
select Change to change the default sender that the service will use, and select Save

String smsSenderId='8e222534-7f05-4972-86e3-17c5d9f894e2'

You can leave out this argument if your service only has one text message sender, or if you want to use the default sender.

Response

If the request to the client is successful, the client returns a SendSmsResponse:

UUID notificationId;
Optional<String> reference;
UUID templateId;
int templateVersion;
String templateUri;
String body;
Optional<String> fromNumber;

If you are using the test API key, all your messages come back with a delivered status.

All messages sent using the team and guest list or live keys appear on your dashboard.

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

httpResult	Message	How to fix
`400`	`[{` `"error": "BadRequestError",` `"message": "Can't send to this recipient using a team-only API key"` `}]`	Use the correct type of API key
`400`	`[{` `"error": "BadRequestError",` `"message": "Can't send to this recipient when service is in trial mode - see https://www.notifications.service.gov.uk/trial-mode"` `}]`	Your service cannot send this notification in trial mode
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information
`429`	`[{` `"error": "RateLimitError",` `"message": "Exceeded rate limit for key type TEAM/TEST/LIVE of 3000 requests per 60 seconds"` `}]`	Refer to API rate limits for more information
`429`	`[{` `"error": "TooManyRequestsError",` `"message": "Exceeded send limits (LIMIT NUMBER) for today"` `}]`	Refer to service limits for the limit number
`500`	`[{` `"error": "Exception",` `"message": "Internal server error"` `}]`	Notify was unable to process the request, resend your notification

Send an email

Method

SendEmailResponse response = client.sendEmail(
    templateId,
    emailAddress,
    personalisation,
    reference,
    emailReplyToId
);

Arguments

templateId (required)

To find the template ID:

Sign in to GOV.UK Notify.
Go to the Templates page and select the relevant template.
Select Copy template ID to clipboard.

For example:

String templateId="f33517ff-2a88-4f6e-b855-c550268ce08a";

emailAddress (required)

The email address of the recipient.

String emailAddress='sender@something.com';

personalisation (required)

If a template has placeholder fields for personalised information such as name or application date, you must provide their values in a map. For example:

Map<String, Object> personalisation = new HashMap<>();
personalisation.put("first_name", "Amala");
personalisation.put("application_date", "2018-01-01");
// pass in a list and it will appear as bullet points in the message:
personalisation.put("list", listOfItems);

If a template does not have any placeholder fields for personalised information, you must pass in an empty map or null.

reference (required)

String reference='STRING';

emailReplyToId (optional)

This is an email address specified by you to receive replies from your users. You must add at least one reply-to email address before your service can go live.

To add a reply-to email address:

Sign in to GOV.UK Notify.
Go to the Settings page.
In the Email section, select Manage on the Reply-to email addresses row.
Select Add reply-to address.
Enter the email address you want to use, and select Add.

String emailReplyToId='8e222534-7f05-4972-86e3-17c5d9f894e2'

You can leave out this argument if your service only has one reply-to email address, or you want to use the default email address.

Response

If the request to the client is successful, the client returns a SendEmailResponse:

UUID notificationId;
Optional<String> reference;
UUID templateId;
int templateVersion;
String templateUri;
String body;
String subject;
Optional<String> fromEmail;

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

httpResult	Message	How to fix
`400`	`[{` `"error": "BadRequestError",` `"message": "Can't send to this recipient using a team-only API key"` `}]`	Use the correct type of API key
`400`	`[{` `"error": "BadRequestError",` `"message": "Can't send to this recipient when service is in trial mode - see https://www.notifications.service.gov.uk/trial-mode"` `}]`	Your service cannot send this notification in trial mode
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information
`429`	`[{` `"error": "RateLimitError",` `"message": "Exceeded rate limit for key type TEAM/TEST/LIVE of 3000 requests per 60 seconds"` `}]`	Refer to API rate limits for more information
`429`	`[{` `"error": "TooManyRequestsError",` `"message": "Exceeded send limits (LIMIT NUMBER) for today"` `}]`	Refer to service limits for the limit number
`500`	`[{` `"error": "Exception",` `"message": "Internal server error"` `}]`	Notify was unable to process the request, resend your notification

Send a file by email

To send a file by email, add a placeholder to the template then upload a file. The placeholder will contain a secure link to download the file.

The links are unique and unguessable. GOV.UK Notify cannot access or decrypt your file.

Your file will be available to download for a default period of 26 weeks (6 months).

To help protect your files you can also:

ask recipients to confirm their email address before downloading
choose the length of time that a file is available to download

Add contact details to the file download page

Sign in to GOV.UK Notify.
Go to the Settings page.
In the Email section, select Manage on the Send files by email row.
Enter the contact details you want to use, and select Save.

Add a placeholder to the template

Sign in to GOV.UK Notify.
Go to the Templates page and select the relevant email template.
Select Edit.
Add a placeholder to the email template using double brackets. For example: “Download your file at: ((link_to_file))”

Your email should also tell recipients how long the file will be available to download.

Upload your file

You can upload PDF, CSV, JSON, .odt, .txt, .rtf, .xlsx and MS Word Document files. Your file must be smaller than 2MB. Contact the GOV.UK Notify team if you need to send other file types.

Convert the PDF to a byte[].
Pass the byte[] to the personalisation argument.
Call the sendEmail method.

For example:

ClassLoader classLoader = getClass().getClassLoader();
File file = new File(classLoader.getResource("document_to_upload.pdf").getFile());
byte [] fileContents = FileUtils.readFileToByteArray(file);

HashMap<String, Object> personalisation = new HashMap();
personalisation.put("link_to_file", client.prepareUpload(fileContents));
client.sendEmail(templateId,
                 emailAddress,
                 personalisation,
                 reference,
                 emailReplyToId);

Set the filename

To do this you will need version 5.0.0-RELEASE of the Java client library, or a more recent version.

You should provide a filename when you upload your file.

The filename should tell the recipient what the file contains. A memorable filename can help the recipient to find the file again later.

The filename must end with a file extension. For example, .csv for a CSV file. If you include the wrong file extension, recipients may not be able to open your file.

If you do not provide a filename for your file, Notify will:

generate a random filename
try to add the correct file extension

If Notify cannot add the correct file extension, recipients may not be able to open your file.

ClassLoader classLoader = getClass().getClassLoader();
File file = new File(classLoader.getResource("document_to_upload.pdf").getFile());
byte [] fileContents = FileUtils.readFileToByteArray(file);

HashMap<String, Object> personalisation = new HashMap();
personalisation.put("link_to_file", client.prepareUpload(fileContents, "report.csv"));
client.sendEmail(templateId,
                 emailAddress,
                 personalisation,
                 reference,
                 emailReplyToId);

Ask recipients to confirm their email address before they can download the file

When a recipient clicks the link in the email you’ve sent them, they have to enter their email address. Only someone who knows the recipient’s email address can download the file.

This security feature is turned on by default.

Turn off email address check (not recommended)

If you do not want to use this feature, you can turn it off on a file-by-file basis.

To do this you will need version 3.19.0-RELEASE of the Java client library, or a more recent version.

You should not turn this feature off if you send files that contain:

personally identifiable information
commercially sensitive information
information classified as ‘OFFICIAL’ or ‘OFFICIAL-SENSITIVE’ under the Government Security Classifications policy

To let the recipient download the file without confirming their email address, set the confirmEmailBeforeDownload flag to false.

ClassLoader classLoader = getClass().getClassLoader();
File file = new File(classLoader.getResource("document_to_upload.pdf").getFile());
byte [] fileContents = FileUtils.readFileToByteArray(file);

HashMap<String, Object> personalisation = new HashMap();
personalisation.put("link_to_file", client.prepareUpload(fileContents, false, false, "52 weeks"));
client.sendEmail(templateId,
                 emailAddress,
                 personalisation,
                 reference,
                 emailReplyToId);

Choose the length of time that a file is available to download

Set the number of weeks you want the file to be available using the retention_period parameter.

To use this feature you will need 3.19.0-RELEASE of the Java client library, or a more recent version.

You can choose any value between 1 week and 78 weeks. When deciding this, you should consider:

the need to protect the recipient’s personal information
whether the recipient will need to download the file again later

If you do not choose a value, the file will be available for the default period of 26 weeks (6 months).

Files sent before 12 April 2023 had a longer default period of 78 weeks (18 months).

ClassLoader classLoader = getClass().getClassLoader();
File file = new File(classLoader.getResource("document_to_upload.pdf").getFile());
byte [] fileContents = FileUtils.readFileToByteArray(file);

HashMap<String, Object> personalisation = new HashMap();
personalisation.put("link_to_file",
                    client.prepareUpload(
                            fileContents,
                            false,
                            false,
                            new RetentionPeriodDuration(52, ChronoUnit.WEEKS)
                    ));
client.sendEmail(templateId,
                 emailAddress,
                 personalisation,
                 reference,
                 emailReplyToId);

Error codes

If the request is not successful, the client returns an HTTPError containing the relevant error code.

error.status_code	error.message	How to fix
`400`	`[{` `"error": "BadRequestError",` `"message": "Can't send to this recipient using a team-only API key"` `}]`	Use the correct type of API key
`400`	`[{` `"error": "BadRequestError",` `"message": "Can't send to this recipient when service is in trial mode - see https://www.notifications.service.gov.uk/trial-mode"` `}]`	Your service cannot send this notification in trial mode
`400`	`[{` `"error": "BadRequestError",` `"message": "Unsupported file type '(FILE TYPE)'. Supported types are: '(ALLOWED TYPES)'"` `}]`	Wrong file type. You can only upload .pdf, .csv, .txt, .doc, .docx, .xlsx, .rtf or .odt files
`400`	`[{` `"error": "BadRequestError",` "message": "`filename` cannot be longer than 100 characters" `}]`	Choose a shorter filename
`400`	`[{` `"error": "BadRequestError",` "message": "`filename` must end with a file extension. For example, filename.csv" `}]`	Include the file extension in your filename
`400`	`[{` `"error": "BadRequestError",` `"message": "Unsupported value for retention_period '(PERIOD)'. Supported periods are from 1 to 78 weeks."` `}]`	Choose a period between 1 and 78 weeks
`400`	`[{` `"error": "BadRequestError",` `"message": "Unsupported value for confirm_email_before_download: '(VALUE)'. Use a boolean true or false value."` `}]`	Use either true or false
`400`	`[{` `"error": "BadRequestError",` `"message": "File did not pass the virus scan"` `}]`	The file contains a virus
`400`	`[{` `"error": "BadRequestError",` `"message": "Send files by email has not been set up - add contact details for your service at https://www.notifications.service.gov.uk/services/(SERVICE ID)/service-settings/send-files-by-email"` `}]`	See how to add contact details to the file download page
`400`	`[{` `"error": "BadRequestError",` `"message": "Can only send a file by email"` `}]`	Make sure you are using an email template
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct type of API key
`413`	`File is larger than 2MB`	The file is too big. Files must be smaller than 2MB
`429`	`[{` `"error": "RateLimitError",` `"message": "Exceeded rate limit for key type TEAM/TEST/LIVE of 3000 requests per 60 seconds"` `}]`	Refer to API rate limits for more information
`429`	`[{` `"error": "TooManyRequestsError",` `"message": "Exceeded send limits (LIMIT NUMBER) for today"` `}]`	Refer to service limits for the limit number
`500`	`[{` `"error": "Exception",` `"message": "Internal server error"` `}]`	Notify was unable to process the request, resend your notification.

Send a letter

When you add a new service it will start in trial mode. You can only send letters when your service is live.

To send Notify a request to go live:

Sign in to GOV.UK Notify.
Go to the Settings page.
In the Your service is in trial mode section, select request to go live.

Method

SendLetterResponse response = client.sendLetter(
    templateId,
    personalisation,
    reference
);

Arguments

templateId (required)

To find the template ID:

Sign in to GOV.UK Notify.
Go to the Templates page and select the relevant template.
Select Copy template ID to clipboard.

For example:

String templateId = "f33517ff-2a88-4f6e-b855-c550268ce08a";

personalisation (required)

The personalisation argument always contains the following parameters for the letter recipient’s address:

address_line_1
address_line_2
address_line_3
address_line_4
address_line_5
address_line_6
address_line_7

The address must have at least 3 lines.

The last line needs to be a real UK postcode or the name of a country outside the UK.

Notify checks for international addresses and will automatically charge you the correct postage.

The postcode personalisation argument has been replaced. If your template still uses postcode, Notify will treat it as the last line of the address.

Any other placeholder fields included in the letter template also count as required parameters. You must provide their values in a map. For example:

Map<String, Object> personalisation = new HashMap<>();
personalisation.put("address_line_1", "The Occupier"); // mandatory address field
personalisation.put("address_line_2", "Flat 2"); // mandatory address field
personalisation.put("address_line_3", "SW14 6BH"); // mandatory address field, must be a real UK postcode
personalisation.put("first_name", "Amala"); // field from template
personalisation.put("application_date", "2018-01-01"); // field from template
// pass in a list and it will appear as bullet points in the letter:
personalisation.put("list", listOfItems);

If a template does not have any placeholder fields for personalised information, you must pass in an empty map or null.

reference (required)

String reference='STRING';

Response

If the request to the client is successful, the client returns a SendLetterResponse:

UUID notificationId;
Optional<String> reference;
UUID templateId;
int templateVersion;
String templateUri;
String body;
String subject;

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

httpResult	Message	How to fix
`403`	`[{` `"error": "BadRequestError",` `"message": "Cannot send letters with a team api key"` `}]`	Use the correct type of API key.
`400`	`[{` `"error": "BadRequestError",` `"message": "Cannot send letters when service is in trial mode - see https://www.notifications.service.gov.uk/trial-mode"` `}]`	Your service cannot send this notification in trial mode.
`400`	`[{` `"error": "ValidationError",` `"message": "personalisation address_line_1 is a required property"` `}]`	Ensure that your template has a field for the first line of the address, refer to personalisation for more information.
`400`	`[{` `"error": "ValidationError",` `"message": "Must be a real UK postcode"` `}]`	Ensure that the value for the last line of the address is a real UK postcode.
`400`	`[{` `"error": "ValidationError",` `"message": "Last line of address must be a real UK postcode or another country"` `}]`	Ensure that the value for the last line of the address is a real UK postcode or the name of a country outside the UK.
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock.
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information.
`429`	`[{` `"error": "RateLimitError",` `"message": "Exceeded rate limit for key type TEAM/TEST/LIVE of 3000 requests per 60 seconds"` `}]`	Refer to API rate limits for more information.
`429`	`[{` `"error": "TooManyRequestsError",` `"message": "Exceeded send limits (LIMIT NUMBER) for today"` `}]`	Refer to service limits for the limit number.
`500`	`[{` `"error": "Exception",` `"message": "Internal server error"` `}]`	Notify was unable to process the request, resend your notification.

Send a precompiled letter

Method

LetterResponse response = client.sendPrecompiledLetter(
    reference,
    precompiledPDFAsFile
    );

LetterResponse response = client.sendPrecompiledLetterWithInputStream(
    reference,
    precompiledPDFAsInputStream
    );

LetterResponse response = client.sendPrecompiledLetter(
    reference,
    precompiledPDFAsFile,
    postage
    );

LetterResponse response = client.sendPrecompiledLetterWithInputStream(
    reference,
    precompiledPDFAsInputStream,
    postage
    );

Arguments

reference (required)

A unique identifier you create. This reference identifies a single unique notification or a batch of notifications. It must not contain any personal information such as name or postal address.

String reference="STRING";

precompiledPDFAsFile (required for the sendPrecompiledLetter method)

The precompiled letter must be a PDF file which meets the GOV.UK Notify letter specification.

This argument adds the precompiled letter PDF file to a Java file object. The method sends this Java file object to GOV.UK Notify.

File precompiledPDF = new File("<PDF file path>");

precompiledPDFAsInputStream (required for the sendPrecompiledLetterWithInputStream method)

The precompiled letter must be an InputStream. This argument adds the precompiled letter PDF content to a Java InputStream object. The method sends this InputStream to GOV.UK Notify.

InputStream precompiledPDFAsInputStream = new FileInputStream(pdfContent);

postage (optional)

You can choose first or second class postage for your precompiled letter. Set the value to first for first class, or second for second class. If you do not pass in this argument, the postage will default to second class.

Response

If the request to the client is successful, the client returns a LetterResponse:

UUID notificationId;
String reference;
String postage

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

httpResult	Message	How to fix
`403`	`[{` `"error": "BadRequestError",` `"message": "Cannot send letters with a team api key"` `}]`	Use the correct type of API key
`400`	`[{` `"error": "BadRequestError",` `"message": "Cannot send letters when service is in trial mode - see https://www.notifications.service.gov.uk/trial-mode"` `}]`	Your service cannot send this notification in trial mode
`400`	`[{` `"error": "ValidationError",` `"message": "personalisation address_line_1 is a required property"` `}]`	Send a valid PDF file
`400`	`[{` `"error": "ValidationError",` `"message": "reference is a required property"` `}]`	Add a reference argument to the method call
`400`	`[{` `"error": "ValidationError",` `"message": "postage invalid. It must be either first or second. "` `}]`	Change the value of postage argument in the method call to either ‘first’ or ‘second’
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information
`429`	`[{` `"error": "RateLimitError",` `"message": "Exceeded rate limit for key type TEAM/TEST/LIVE of 3000 requests per 60 seconds"` `}]`	Refer to API rate limits for more information
`429`	`[{` `"error": "TooManyRequestsError",` `"message": "Exceeded send limits (LIMIT NUMBER) for today"` `}]`	Refer to service limits for the limit number
`400`	`"message":"precompiledPDF must be a valid PDF file"`	Send a valid PDF file
`400`	`"message":"reference cannot be null or empty"`	Populate the reference parameter
`400`	`"message":"precompiledPDF cannot be null or empty"`	Send a PDF file with data in it

Get message status

Get the status of one message

You can only get the status of messages sent within the retention period. The default retention period is 7 days.

Method

Notification notification = client.getNotificationById(notificationId);

Arguments

notificationId (required)

The ID of the notification. To find the notification ID, you can either:

check the response to the original notification method call
sign in to GOV.UK Notify and go to the API integration page

Response

If the request to the client is successful, the client returns a Notification:

UUID id;
Optional<String> reference;
Optional<String> emailAddress;
Optional<String> phoneNumber;
Optional<String> line1;
Optional<String> line2;
Optional<String> line3;
Optional<String> line4;
Optional<String> line5;
Optional<String> line6;
Optional<String> line7;
Optional<String> postage;
String notificationType;
String status;
UUID templateId;
int templateVersion;
String templateUri;
String body;
Optional<String subject;
ZonedDateTime createdAt;
Optional<ZonedDateTime> sentAt;
Optional<ZonedDateTime> completedAt;
Optional<ZonedDateTime> estimatedDelivery;
Optional<String> createdByName;

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

httpResult	Message	How to fix
`400`	`[{` `"error": "ValidationError",` `"message": "id is not a valid UUID"` `}]`	Check the notification ID
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information
`404`	`[{` `"error": "NoResultFound",` `"message": "No result found"` `}]`	Check the notification ID

Get the status of multiple messages

This API call returns one page of up to 250 messages and statuses. You can get either the most recent messages, or get older messages by specifying a particular notification ID in the olderThanId argument.

You can only get the status of messages that are 7 days old or newer.

Method

NotificationList notification = client.getNotifications(
    status,
    notificationType,
    reference,
    olderThanId
);

To get the most recent messages, you must pass in an empty olderThanId argument or null.

To get older messages, pass the ID of an older notification into the olderThanId argument. This returns the next oldest messages from the specified notification ID.

Arguments

You can pass in empty arguments or null to ignore these filters.

status (optional)

You can filter by each:

email status
text message status
letter status
precompiled letter status

You can leave out this argument to ignore this filter.

notificationType (optional)

You can filter by:

email
sms
letter

reference (optional)

A unique identifier you create if necessary. This reference identifies a single unique notification or a batch of notifications. It must not contain any personal information such as name or postal address.

String reference='STRING';

olderThanId (optional)

Input the ID of a notification into this argument. If you use this argument, the client returns the next 250 received notifications older than the given ID.

String olderThanId='8e222534-7f05-4972-86e3-17c5d9f894e2'

If you pass in an empty argument or null, the client returns the most recent 250 notifications.

Response

If the request to the client is successful, the client returns a NotificationList:

List<Notification> notifications;
String currentPageLink;
Optional<String> nextPageLink;

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

httpResult	Message	How to fix
`400`	`[{` `"error": "ValidationError",` `"message": "bad status is not one of [created, sending, sent, delivered, pending, failed, technical-failure, temporary-failure, permanent-failure, accepted, received]"` `}]`	Contact the GOV.UK Notify team
`400`	`[{` `"error": "ValidationError",` `"message": "Applet is not one of [sms, email, letter]"` `}]`	Contact the GOV.UK Notify team
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information

Email status descriptions

Status	Description
`created`	GOV.UK Notify has placed the message in a queue, ready to be sent to the provider. It should only remain in this state for a few seconds.
`sending`	GOV.UK Notify has sent the message to the provider. The provider will try to deliver the message to the recipient for up to 72 hours. GOV.UK Notify is waiting for delivery information.
`delivered`	The message was successfully delivered.
`permanent-failure`	The provider could not deliver the message because the email address was wrong. You should remove these email addresses from your database.
`temporary-failure`	The provider could not deliver the message. This can happen when the recipient’s inbox is full or their anti-spam filter rejects your email. Check your content does not look like spam before you try to send the message again.
`technical-failure`	Your message was not sent because there was a problem between Notify and the provider. You’ll have to try sending your messages again.

Text message status descriptions

Status	Description
`created`	GOV.UK Notify has placed the message in a queue, ready to be sent to the provider. It should only remain in this state for a few seconds.
`sending`	GOV.UK Notify has sent the message to the provider. The provider will try to deliver the message to the recipient for up to 72 hours. GOV.UK Notify is waiting for delivery information.
`pending`	GOV.UK Notify is waiting for more delivery information. GOV.UK Notify received a callback from the provider but the recipient’s device has not yet responded. Another callback from the provider determines the final status of the text message.
`sent`	The message was sent to an international number. The mobile networks in some countries do not provide any more delivery information. The GOV.UK Notify website displays this status as ‘Sent to an international number’.
`delivered`	The message was successfully delivered.
`permanent-failure`	The provider could not deliver the message. This can happen if the phone number was wrong or if the network operator rejects the message. If you’re sure that these phone numbers are correct, you should contact GOV.UK Notify support. If not, you should remove them from your database. You’ll still be charged for text messages that cannot be delivered.
`temporary-failure`	The provider could not deliver the message. This can happen when the recipient’s phone is off, has no signal, or their text message inbox is full. You can try to send the message again. You’ll still be charged for text messages to phones that are not accepting messages.
`technical-failure`	Your message was not sent because there was a problem between Notify and the provider. You’ll have to try sending your messages again. You will not be charged for text messages that are affected by a technical failure.

Letter status descriptions

Status	Description
`accepted`	GOV.UK Notify has sent the letter to the provider to be printed.
`received`	The provider has printed and dispatched the letter.
`cancelled`	Sending cancelled. The letter will not be printed or dispatched.
`technical-failure`	GOV.UK Notify had an unexpected error while sending the letter to our printing provider.
`permanent-failure`	The provider cannot print the letter. Your letter will not be dispatched.

Precompiled letter status descriptions

Status	Description
`accepted`	GOV.UK Notify has sent the letter to the provider to be printed.
`received`	The provider has printed and dispatched the letter.
`cancelled`	Sending cancelled. The letter will not be printed or dispatched.
`pending-virus-check`	GOV.UK Notify has not completed a virus scan of the precompiled letter file.
`virus-scan-failed`	GOV.UK Notify found a potential virus in the precompiled letter file.
`validation-failed`	Content in the precompiled letter file is outside the printable area. See the GOV.UK Notify letter specification for more information.
`technical-failure`	GOV.UK Notify had an unexpected error while sending the letter to our printing provider.
`permanent-failure`	The provider cannot print the letter. Your letter will not be dispatched.

Get a PDF for a letter notification

Method

This returns the PDF contents of a letter notification.

byte[] pdfFile = client.getPdfForLetter(notificationId)

Arguments

notificationId (required)

The ID of the notification. To find the notification ID, you can either:

check the response to the original notification method call
sign in to GOV.UK Notify and go to the API integration page

Response

If the request to the client is successful, the client will return a byte[] object containing the raw PDF data.

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

error.status_code	error.message	How to fix
`400`	`[{` `"error": "ValidationError",` `"message": "id is not a valid UUID"` `}]`	Check the notification ID
`400`	`[{` `"error": "PDFNotReadyError",` `"message": "PDF not available yet, try again later"` `}]`	Wait for the notification to finish processing. This usually takes a few seconds
`400`	`[{` `"error": "BadRequestError",` `"message": "File did not pass the virus scan"` `}]`	You cannot retrieve the contents of a letter notification that contains a virus
`400`	`[{` `"error": "BadRequestError",` `"message": "PDF not available for letters in technical-failure"` `}]`	You cannot retrieve the contents of a letter notification in technical-failure
`400`	`[{` `"error": "ValidationError",` `"message": "Notification is not a letter"` `}]`	Check that you are looking up the correct notification
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information
`404`	`[{` `"error": "NoResultFound",` `"message": "No result found"` `}]`	Check the notification ID

Get a template

Get a template by ID

Method

This returns the latest version of the template.

Template template = client.getTemplateById(templateId);

Arguments

templateId (required)

The ID of the template. Sign in to GOV.UK Notify and go to the Templates page to find it.

String templateId='f33517ff-2a88-4f6e-b855-c550268ce08a';

Response

If the request to the client is successful, the client returns a Template:

UUID id;
String name;
String templateType;
ZonedDateTime createdAt;
Optional<ZonedDateTime> updatedAt;
String createdBy;
int version;
String body;
Optional<String> subject;
Optional<Map<String, Object>> personalisation;
Optional<String> letterContactBlock;

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

httpResult	Message	How to fix
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information
`404`	`[{` `"error": "NoResultFound",` `"message": "No Result Found"` `}]`	Check your template ID

Get a template by ID and version

Method

Template template = client.getTemplateVersion(templateId, version);

Arguments

templateId (required)

The ID of the template. Sign in to GOV.UK Notify and go to the Templates page to find it.

String templateId='f33517ff-2a88-4f6e-b855-c550268ce08a';

version (required)

The version number of the template.

Response

If the request to the client is successful, the client returns a Template:

UUID id;
String name;
String templateType;
ZonedDateTime createdAt;
Optional<ZonedDateTime> updatedAt;
String createdBy;
int version;
String body;
Optional<String> subject;
Optional<Map<String, Object>> personalisation;
Optional<String> letterContactBlock;

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

httpResult	message	How to fix
`400`	`[{` `"error": "ValidationError",` `"message": "id is not a valid UUID"` `}]`	Check the notification ID
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information
`404`	`[{` `"error": "NoResultFound",` `"message": "No Result Found"` `}]`	Check your template ID and version

Get all templates

Method

This returns the latest version of all templates.

TemplateList templates = client.getAllTemplates(templateType);

Arguments

templateType (optional)

If you do not use templateType, the client returns all templates. Otherwise you can filter by:

email
sms
letter

Response

If the request to the client is successful, the client returns a TemplateList:

List<Template> templates;

If no templates exist for a template type or there no templates for a service, the templates list is empty.

Generate a preview template

Method

This generates a preview version of a template.

TemplatePreview templatePreview = client.generateTemplatePreview(
    templateId,
    personalisation
);

The parameters in the personalisation argument must match the placeholder fields in the actual template. The API notification client ignores any extra fields in the method.

Arguments

templateId (required)

The ID of the template. Sign in to GOV.UK Notify and go to the Templates page to find it.

String templateId='f33517ff-2a88-4f6e-b855-c550268ce08a';

personalisation (required)

If a template has placeholder fields for personalised information such as name or application date, you must provide their values in a map. For example:

Map<String, Object> personalisation = new HashMap<>();
personalisation.put("first_name", "Amala");
personalisation.put("application_date", "2018-01-01");

If a template does not have any placeholder fields for personalised information, you must pass in an empty map or null.

Response

If the request to the client is successful, the client returns a TemplatePreview:

UUID id;
String templateType;
int version;
String body;
Optional<String> subject;
Optional<String> html;

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

httpResult	message	How to fix
`400`	`[{` `"error": "BadRequestError",` `"message": "Missing personalisation: [PERSONALISATION FIELD]"` `}]`	Check that the personalisation arguments in the method match the placeholder fields in the template
`400`	`[{` `"error": "NoResultFound",` `"message": "No result found"` `}]`	Check the template ID
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information

Get received text messages

This API call returns one page of up to 250 received text messages. You can get either the most recent messages, or get older messages by specifying a particular notification ID in the olderThanId argument.

You can only get messages that are 7 days old or newer.

You can also set up callbacks for received text messages.

Enable received text messages

To receive text messages:

Go to the Text message settings section of the Settings page.
Select Change on the Receive text messages row.

Get a page of received text messages

Method

ReceivedTextMessageList response = client.getReceivedTextMessages(olderThanId);

To get the most recent messages, you must pass in an empty argument or null.

To get older messages, pass the ID of an older notification into the olderThanId argument. This returns the next oldest messages from the specified notification ID.

Arguments

olderThanId (optional)

Input the ID of a received text message into this argument. If you use this argument, the client returns the next 250 received text messages older than the given ID.

String olderThanId='8e222534-7f05-4972-86e3-17c5d9f894e2'

If you pass in an empty argument or null, the client returns the most recent 250 text messages.

Response

If the request to the client is successful, the client returns a ReceivedTextMessageList that returns all received texts.

private List<ReceivedTextMessage> receivedTextMessages;
private String currentPageLink;
private String nextPageLink;

The ReceivedTextMessageList has the following properties:

private UUID id;
private String notifyNumber;
private String userNumber;
private UUID serviceId;
private String content;
private ZonedDateTime createdAt;

If the notification specified in the olderThanId argument is older than 7 days, the client returns an empty response.

Error codes

If the request is not successful, the client returns a NotificationClientException containing the relevant error code:

httpResult	Message	How to fix
`403`	`[{` `"error": "AuthError",` `"message": "Error: Your system clock must be accurate to within 30 seconds"` `}]`	Check your system clock
`403`	`[{` `"error": "AuthError",` `"message": "Invalid token: API key not found"` `}]`	Use the correct API key. Refer to API keys for more information

Error messages

Error messages consist of:

a status_code, for example ‘400’
an error, for example ’BadRequestError’
a message, for example ‘Mobile numbers can only include: 0 1 2 3 4 5 6 7 8 9 ( ) + -‘

Do not use the content of the messages in your code. These can sometimes change, which may affect your API integration.

Use the status_code or the error instead, as these will not change.

Find error codes in:

send a message
get message status
get a template
get received text messages

Testing

All testing takes place in the production environment. There is no test environment for GOV.UK Notify.

Smoke testing

If you need to smoke test your integration with Notify on a regular basis, you must use the following smoke test phone numbers and email addresses.

Phone numbers

07700900000
07700900111
07700900222

Email addresses

simulate-delivered@notifications.service.gov.uk
simulate-delivered-2@notifications.service.gov.uk
simulate-delivered-3@notifications.service.gov.uk

The smoke test phone numbers and email addresses will validate the request and simulate a successful response, but will not send a real message, produce a delivery receipt or persist the notification to the database.

You can use these smoke test numbers and addresses with any type of API key.

You can smoke test all Notify API client functions except:

Get the status of one message
Get the status of all messages

You cannot use the smoke test phone numbers or email address with these functions because they return a fake notification_ID. If you need to test these functions, use a test API key and any other phone number or email.

Other testing

You must use a test API key to do non-smoke testing such as performance or integration testing. You can use any non-smoke testing phone numbers or email addresses. You do not need a specific Notify testing account.

API keys

There are three different types of API keys:

test
team and guest list
live

When you set up a new service it will start in trial mode. A service in trial mode can create test and team and guest list keys. You must have a live service to create a live key.

To create an API key:

Sign in to GOV.UK Notify.
Go to the API integration page.
Select API keys.
Select Create an API key.

Test

Use a test key to test the performance of your service and its integration with GOV.UK Notify.

Messages sent using a test key:

generate realistic responses
result in a delivered status
are not actually delivered to a recipient
do not appear on your dashboard
do not count against your text message and email allowances

To test failure responses with a test key, use the following numbers and addresses:

Phone number/Email address	Response
07700900003	`temporary-failure`
07700900002	`permanent-failure`
temp-fail@simulator.notify	`temporary-failure`
perm-fail@simulator.notify	`permanent-failure`
any other valid number or address	`delivered`

You do not have to revoke test keys.

Team and guest list

A team and guest list key lets you send real messages to your team members and addresses/numbers on your guest list while your service is still in trial mode.

You will get an error if you use these keys to send messages to anyone who is not on your team or your guest list.

Messages sent with a team and guest list key appear on your dashboard and count against your text message and email allowances.

You do not have to revoke team and guest list keys.

Live

You can only create live keys once your service is live. You can use live keys to send messages to anyone.

Messages sent with a live key appear on your dashboard and count against your text message and email allowances.

You should revoke and re-create these keys on a regular basis. To revoke a key:

Sign in to GOV.UK Notify.
Go to the API integration page.
Select API keys.
Select Revoke for the API key you want to revoke.

You can have more than one active key at a time.

You should never send test messages to invalid numbers or addresses using a live key.

Limits

Rate limits

You’re limited to sending 3,000 messages per minute.

This limit is calculated on a rolling basis, per API key type. If you exceed the limit, you will get a 429 error RateLimitError.

Daily limits

There’s a limit to the number of messages you can send each day:

Service status	Type of API key	Daily limit
Live	Team or live	250,000 emails 250,000 text messages 20,000 letters
Trial	Team	50 emails or text messages
Live or trial	Test	Unlimited

These limits reset at midnight.

Phone network limits

If you repeatedly send text messages to the same number the phone networks will block them.

There’s an hourly limit of:

20 messages with the same content
100 messages with any content

Your messages may not be delivered if you exceed these limits.

Callbacks

Callbacks are when GOV.UK Notify sends POST requests to your service. You can get callbacks when:

a text message or email you’ve sent is delivered or fails
your service receives a text message

Set up callbacks

You must provide:

a URL where Notify will post the callback to
a bearer token which Notify will put in the authorisation header of the requests

To do this:

Sign in to GOV.UK Notify.
Go to the API integration page.
Select Callbacks.

Retry callbacks

If Notify sends a POST request to your service, but the request fails then we will retry.

We will retry every 5 minutes, up to a maximum of 5 times.

Delivery receipts

When you send an email or text message, Notify will send a receipt to your callback URL with the status of the message. This is an automated method to get the status of messages.

This functionality works with test API keys, but does not work with smoke testing phone numbers or email addresses.

The callback message is formatted in JSON. All of the values are strings, apart from the template version, which is a number. The key, description and format of the callback message arguments will be:

Key	Description	Format
`id`	Notify’s id for the status receipts	UUID
`reference`	The reference sent by the service	`12345678` or null
`to`	The email address or phone number of the recipient	`hello@gov.uk` or `07700912345`
`status`	The status of the notification	`delivered`, `permanent-failure`, `temporary-failure` or `technical-failure`
`created_at`	The time the service sent the request	`2017-05-14T12:15:30.000000Z`
`completed_at`	The last time the status was updated	`2017-05-14T12:15:30.000000Z` or null
`sent_at`	The time the notification was sent	`2017-05-14T12:15:30.000000Z` or null
`notification_type`	The notification type	`email` or `sms`
`template_id`	The id of the template that was used	UUID
`template_version`	The version number of the template that was used	`1`

Received text messages

If your service receives text messages in Notify, Notify can forward them to your callback URL as soon as they arrive.

Contact the Notify team using the support page or chat to us on Slack to request a unique number for text message replies.

The callback message is formatted in JSON. All of the values are strings. The key, description and format of the callback message arguments will be:

Key	Description	Format
`id`	Notify’s id for the received message	UUID
`source_number`	The phone number the message was sent from	447700912345
`destination_number`	The number the message was sent to (your number)	07700987654
`message`	The received message	Hello Notify!
`date_received`	The UTC datetime that the message was received by Notify	2017-05-14T12:15:30.000000Z

API architecture

Architecture for sending a text message

The service sends a text message notification to Notify.
Notify sends the text message to the provider.
The provider delivers the text message to the recipient.
The recipient receives the text message and sends a delivery receipt to the provider.
The provider sends the delivery receipt to Notify.
Notify receives the delivery receipt and sends an API response to the service.
The service receives the API response.