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Guidance

Apply for an increase in tax credits for a backdated disability benefit decision

Ask for a backdated disability benefit decision to be included in a period when you were claiming Working Tax Credit or Child Tax Credit.

From:
HM Revenue & Customs
Published:
6 October 2026

If you have received a backdated disability benefit decision for a period when you were claiming tax credits, you can ask HMRC to pay you extra tax credits for that period.

You must submit your application within one month of being told either:

  • you qualify for the backdated disability benefit
  • the rate of your backdated disability benefit has been increased

Before you start

Read Tax credits disability helpsheet TC956 to find out all the conditions you need to meet to get the tax credits payment.

How to apply

Tell HMRC about a backdated disability benefit decision for an adult

Use this form to tell HMRC about a backdated decision for Working Tax Credit.

Tax credits: adult disability backdating form (TC-DB1)

PDF, 863 KB, 4 pages

This file may not be suitable for users of assistive technology.

Request an accessible format
If you use assistive technology (such as a screen reader) and need a version of this document in a more accessible format, please email different.format@hmrc.gov.uk. Please tell us what format you need. It will help us if you say what assistive technology you use.

Email HMRC to ask for the form in Welsh.

Tell HMRC about a backdated disability benefit decision for a child

Use this form to tell HMRC about a backdated decision for Child Tax Credit.

Tax credits: child disability backdating form (TC-DB2)

PDF, 849 KB, 3 pages

This file may not be suitable for users of assistive technology.

Request an accessible format
If you use assistive technology (such as a screen reader) and need a version of this document in a more accessible format, please email different.format@hmrc.gov.uk. Please tell us what format you need. It will help us if you say what assistive technology you use.

Email HMRC to ask for the form in Welsh.

If you use assistive technology

These files may not be suitable if you use assistive technology (such as a screen reader). If you need a more accessible format, email different.format@hmrc.gov.uk and tell us what format you need. It will help if you tell us what assistive technology you use. Read the accessibility statement for HMRC forms.

How to complete the form

You need to:

  1. Open the form you need on your computer using the latest free version of Adobe Reader.
  2. Complete it on-screen.
  3. Save the updated form on your computer.
  4. Email it to HMRC using the address in the ‘What you need to do now’ section of the form.

The form may not work if you try to open it in your internet browser. If the form does not open, contact online services support for more help.

You could be fined up to £3,000 if you give wrong information.

After you’ve applied

HMRC will:

  • check your claim
  • phone or write to you to tell you if you qualify for a backdated payment and how it will be paid

Sign up for emails or print this page

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