Last checked: 9 September 2026 · Source: GOV.UK
The Final Declaration is the year-end submission that replaces your old Self Assessment tax return (SA100) once you're in MTD for Income Tax. Due by 31 January following the end of the tax year. The same deadline as the current Self Assessment return, just a different route to get there.
For the 2026/27 tax year, that's 31 January 2028. For 2027/28, it's 31 January 2029.
Before the Final Declaration itself, GOV.UK's current guidance on using MTD for Income Tax describes confirming an "end of period statement" for each business, self-employment or property, once your quarterly updates for the year are in. This step finalises the figures for that specific business, confirming they're accurate and complete before anything gets carried into your overall tax position. If you run more than one business, this happens once per business.
We've also seen an older 2023 announcement suggesting HMRC intended to simplify or fold this step into the Final Declaration itself, and some newer commentary describes the two as merged in practice. Live GOV.UK guidance still lists confirming end of period statements as a distinct action, so treat it as a real step for now, and check with your software provider exactly how their product presents it, since the interface may combine both steps into what feels like one screen even if they're technically separate.
It's submitted through your MTD-compatible software, not on paper and not through the standard HMRC portal.
Your balancing payment is still due 31 January. Any payment on account is still due 31 July. The Final Declaration changes how you submit. It doesn't change when you pay.
Every Final Declaration deadline, 2028 through 2030, is already in the calendar with a full reminder cascade.