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Guidance

Edition 2: Making Tax Digital for Income Tax — software developer newsletter

Published 29 May 2026

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This publication is available at https://www.gov.uk/government/publications/edition-2-making-tax-digital-for-income-tax-software-developer-newsletter/edition-2-making-tax-digital-for-income-tax-software-developer-newsletter

Welcome to the April edition of the Making Tax Digital for Income Tax — software developer newsletter, providing updates on service performance, API changes, and key information following mandation go live.

This edition highlights:

  • ongoing support
  • service stability
  • continued developer engagement

API deprecation and retirement update

API status summary

To help you stay aligned with the latest MTD for Income Tax API changes, the table below provides an update on the status of the API versions.

API Version Status Deprecation date Retirement date Required action
business-details-api V1 retired 16 October 2025 23 April 2026 upgrade to V2
individual-calculations-api V7 retired 16 October 2025 1 May 2026 upgrade to V8

Important notes for developers

Retired API versions no longer work and are no longer supported.

Upgrading is mandatory. Failure to upgrade means your software cannot use these APIs and will no longer appear in Software Choices.

Release highlights

There were no new API releases in April. Activity this month focused on:

  • testing
  • performance assurance
  • preparation for upcoming Income Tax Self Assessment (ITSA) releases

What’s next

Further API lifecycle milestones are expected later in 2026. Developers should review the MTD for Income Tax API Roadmap and plan upgrades early to avoid disruption.

Live service issues

This section highlights:

  • the most common issues reported by software developers in April
  • guidance to help you resolve these issues quickly
  • an understanding of where HMRC is already taking action

Core service Impacts

Theme What’s being reported What developers may wish to check
Obligations and quarterly updates Obligations missing or not returned, or difficulties submitting quarterly updates. A small number of April cases were linked to HMRC data corrections, which are now largely resolved. Some cases require investigation or corrective action by HMRC. Check tax year selection and income source start and end dates, then re‑test obligation retrieval.
Sign up tax year issues At the start of the new tax year, some customers were only presented with a single tax year option during sign up due to delays in removing restrictions within the Signal Control Gateway. As a result, these customers could not select the correct tax year. This issue was caused by HMRC systems and was not customer error. All affected cases require amendment by HMRC and remain dependent on the delivery of related functionality currently being addressed under a separate Live Service Issue. Check tax year alignment for affected customers. Due to sign up system restrictions, some customers were only presented with one tax year option and may remain temporarily aligned to an incorrect year until HMRC amendment functionality is restored.

For the fastest resolution, continue to raise LSIs through your account manager using the makingtaxdigital-softwarevendors@hmrc.gov.uk.

Other known behaviour and planned changes

Other known behaviour and any planned changes that developers may wish to be aware of.

Theme What’s being reported What developers may wish to check
Business details 404 or data consistency behaviours when calling business details or listing businesses. Check for duplicate or inactive income sources and confirm accounting type.
Employment and pension data Errors completing employment pages or pension data, including known state pension pre‑population accuracy issues being addressed by HMRC. Some customers may see an incorrect State Pension amount pre‑populated. Where this happens, customers should override the figure and enter the correct amount based on their own records or State Pension notifications. Software should allow this value to be edited and included correctly in calculations.
Accounting method and annual investment allowance (AIA) Customers are defaulted to the cash basis at sign up and cannot change this in‑year. Claiming AIA in‑year may trigger a validation rule during calculation. Note that this validation behaviour is planned to change in a future release; until then, affected cases may require adjustment.
Authorisation and access issues Client or agent reported as not authorised, including 403 and agent service account (ASA) related access issues. Confirm correct credentials are used and ASA is set up where required.

Service updates

Read the latest planned downtime on the API platform status page.

Customer and agent guidance updates

What’s changed recently

Ahead of 6 April, most sections of the Making Tax Digital for Income Tax service guide were refreshed, including:

  • an updated introduction, confirming key dates and addressing common myths
  • guidance on getting software ready and accessing the MTD service
  • updates covering digital record keeping, income adjustments, and changes in circumstances
  • updated help and support content
  • further improvements to the exemptions guidance

Developers may find it helpful to review the updated guidance to ensure software journeys, help content and customer messaging remain aligned.

What’s coming next

The remaining sections of the MTD guide will be updated next, covering:

  • sending quarterly updates
  • submitting the end of year tax return

Looking ahead to 2026 to 2027, guidance will continue to evolve with a focus on:

  • supporting non‑aligned customers
  • clearer technical guidance, including MTD and penalty reform legislation
  • iterating guidance based on customer usage, planned releases and live service issues
  • better alignment between GOV.UK guidance and the service guide
  • updating the Self Assessment guidance to reflect the full MTD customer journey

Communications update

This section provides an update on recent communications activity related to Making Tax Digital for Income Tax.

Keeping you updated on HMRC communications activity

As we move towards the first quarterly MTD submission deadline, HMRC will continue to share updates on communications plans, priorities and campaign activity.

We’re inviting organisations to share contact details for their communications colleagues to help:

  • support clearer and more timely engagement
  • strengthen collaboration with HMRC
  • enable direct engagement with the HMRC communications team, where needed

If your organisation would find this useful, send an email to makingtaxdigital-softwarevendors@hmrc.gov.uk.

Agent campaign activity

Highlights of the campaign activity include:

Developer engagement and feedback

Views are welcome on how HMRC guidance could be used more effectively within software products. This could include:

  • linking directly to relevant guidance
  • surfacing content within products
  • using HMRC’s digital assistant
  • walking developers through existing guidance content

Ways to engage and provide feedback include:

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