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Check a list of software developers who can provide Customs Declaration Service software.

• Updated: 8 December 2025

Information for developing and testing of software for HMRC forms, returns and messages.

• Updated: 27 November 2013

How to register as a software developer with HMRC.

• Updated: 5 July 2022

Technical specifications for software developers working with the PAYE online service.

• Updated: 1 October 2025

Specifications and guidelines for Real Time Information internet submissions and for the outgoing Data Provisioning Service.

• Updated: 7 August 2025

Use this list to find individual software suppliers and commercial products to use to file online with HMRC online services.

• Updated: 18 March 2014

Find out the expectations for good use of generative artificial intelligence (AI) in commercial software products that help customers submit information to HMRC.

• Updated: 28 January 2026

Find Document Submission Protocol guidance for architects, software developers and other parties interested in building Transaction Engine client applications.

• Updated: 1 January 2014

Support and technical specifications for software developers working with the Self Assessment online service.

• Updated: 20 January 2015

Find software developers that can provide software to let you submit presentation of goods notifications for the safety and security process when goods arrive in Northern Ireland.

• Updated: 13 January 2026