What is a final declaration?

Definition of final declaration

Final declaration is the term used by HMRC to describe the process a taxpayer goes through to finalise their end-of-year position for tax. This process was formerly known as a ‘crystallisation’.

The final declaration process will be introduced in April 2026 as part of the Making Tax Digital for Income Tax initiative. This will replace the annual Self Assessment tax return for many taxpayers, and require affected taxpayers to keep their records digitally and file their tax return through accounting software

Before starting the final declaration process, the taxpayer will need to ensure that their accounting software is up to date with:

  • a finalised end of period statement (EOPS) for each business or type of business income (for example, a taxpayer must file a separate EOPS for income from self-employment and income from letting out a property)
  • their entire income (including interest on savings and dividend payments)
  • any relevant additional information

The final declaration process will then allow the taxpayer to finalise their tax position for the year and calculate their final tax liability.

Disclaimer: The content included in this glossary is based on our understanding of tax law at the time of publication. It may be subject to change and may not be applicable to your circumstances, so should not be relied upon. You are responsible for complying with tax law and should seek independent advice if you require further information about the content included in this glossary. If you don't have an accountant, take a look at our directory to find a FreeAgent Practice Partner based in your local area.

Bookkeeping and tax tips

We are committed to keeping your information safe. Read our Privacy Policy to find out more.

Are you an accountant or bookkeeper?

Find out more about FreeAgent for your practice.