Form

Tax credits: tell HMRC about an adult disability backdating decision (TC-DB1)

Use this form to tell HMRC about a backdated disability benefit decision if you're an adult.

• From: HM Revenue & Customs
• Published: 3 September 2025

Documents

Adult disability backdating form (TC-DB1)

PDF, 863 KB, 4 pages

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Details

To qualify for the disability element of Working Tax Credit, you must tell HMRC within one month of the disability benefit provider’s decision.

You’ll also need to meet the 3 conditions outlined in the Tax credits: disability helpsheet TC956.

Email HMRC to ask for the form in Welsh.

How to complete the form

You need to:

1. Download and save the form on your computer.
2. Open it using the latest free version of Adobe Reader.
3. Complete it on-screen.
4. Send it to HMRC (using the email address given 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.

Published 3 September 2025