What is the final declaration in Making Tax Digital?

The final declaration is HMRC's older name for your yearly tax return under Making Tax Digital. You send it from MTD software by 31 January after the tax year ends, so 2026-27's is due by 31 January 2028.

Under Making Tax Digital for Income Tax (MTD), you send four quarterly updates during the year, then one tax return that finishes the year. HMRC's guidance for software developers now says not to use "final declaration" with customers and to say tax return instead, and GOV.UK does the same. From here on this page says tax return. It follows GOV.UK and HMRC's Developer Hub as checked on 17 October 2026.

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Why the old name still turns up

You will still see "final declaration" in older articles and in some software. HMRC's technical guide says the software tells HMRC you are ready by asking for a tax calculation with a "Final Declaration" setting switched on, and the last call is named "Submit a Self Assessment Final Declaration". Behind the screen, the old name lives on. On your screen, it should say tax return.

What the tax return does

GOV.UK calls quarterly updates "summaries, not tax returns". They give HMRC your running totals of business or rental income and expenses. The tax return is where the year is settled. HMRC's guide describes it as the step that lets you "finalise their tax position" for the year, taking in all your income and gains, and where most formal claims for reliefs and allowances are made.

Part of the tax return	Who does it	Examples from GOV.UK
Year-end adjustments to your business or rental figures	You, in your software	Removing expenses you cannot claim, the trading income allowance, capital allowances, prepayments and accruals
Other income HMRC already knows about	HMRC adds it, you check it	Pay from a job, pensions, taxable state benefits, CIS subcontractor deductions, Marriage Allowance claims
Other income HMRC does not know about	You add it	Savings interest, dividends, your share of partnership profit, other gains not added automatically
The tax calculation	You view and check it	Your software shows it before you send
The declaration	You, or your main agent	That the information is correct and complete to the best of your knowledge

GOV.UK says you must check what HMRC has added before you submit. If you resend your fourth quarterly update to fix your records, do that before you make the tax adjustments.

What this means for you

If you joined MTD on 6 April 2026, your first MTD tax return is for 2026-27. You can send it from 6 April 2027, and it is due by 31 January 2028. Before that, your 2025-26 return is a normal Self Assessment return, due by 31 January 2027.

If you start on 6 April 2027, you send a normal Self Assessment return for 2026-27 by 31 January 2028. Your first MTD tax return is for 2027-28 and is due by 31 January 2029.

Two points catch people out:

Refunds. GOV.UK says: "If you think you are due a tax refund, you cannot claim the refund in your tax return using Making Tax Digital for Income Tax." HMRC adds your CIS deductions to your MTD tax return, and any refund is requested separately through HMRC online services.
Penalties. A late tax return earns one penalty point. At 4 points HMRC charges a £200 penalty, or at 2 points if you volunteered for MTD before you had to. Points below that line drop off 24 months after the missed deadline. Paying late is separate: the tax is still due by 31 January, and under the new rules a penalty starts after 30 days in your first year on the new penalties, and after 15 days from then on. If first-year tax is still unpaid after day 30, both the day-15 and day-30 charges apply. You only get the 30 days once.

MTD does not change how or when you pay. GOV.UK says the return creates your Self Assessment tax bill for the year, with the same payment dates as before.

Steps to send your MTD tax return

Send all four quarterly updates for the year. The fourth is due by 7 May after the year ends.
Correct your records if needed and resend the fourth update before making any tax adjustments.
Make your year-end adjustments, such as removing private use and adding capital allowances.
Ask your software for a calculation and check the income HMRC has added, such as job pay, pensions and CIS deductions.
Add anything HMRC does not hold, such as savings interest and dividends.
Confirm you are ready, check the tax calculation, and declare the information correct and complete.
Look for the message in your software saying it has been submitted, and pay any tax due by 31 January.
If you are due money back, request the refund through your HMRC online services account.

If someone else will send it for you, only a main agent can, and you still check and confirm it in writing first. Our guide to whether an accountant can submit it covers that.

The free MTD check shows when you start and when your first tax return is due. There are more guides in the trades section and the landlord section.

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Questions people ask

Is the final declaration different from a tax return?

No. It is the same year-end step. HMRC's guide for software developers says not to use 'final declaration' with customers and to say tax return instead. The older name survives in HMRC's software connections, where the last step is still called Submit a Self Assessment Final Declaration.

Can I send my tax return straight after 5 April?

GOV.UK says you can send it any time from 6 April after the tax year ends. You need to have sent your quarterly updates first, so in our reading the earliest you can send it is once your fourth update for the year has gone.

Can I claim a tax refund in my Making Tax Digital tax return?

No. GOV.UK says you cannot claim a refund in your tax return using Making Tax Digital for Income Tax. You request it through your HMRC online services account instead, or your agent requests it through their agent services account.

What happens if I send my tax return late?

You get one late submission penalty point. At 4 points HMRC charges a £200 penalty, and £200 again for each later missed deadline. If you volunteered for MTD before you had to, the £200 comes at 2 points. The 2026-27 relief from points covers quarterly updates only, not the tax return.

I found a mistake after sending it. What now?

Change it in your MTD software. GOV.UK says you can change a tax return within 12 months of the submission deadline, and your HMRC online services account then shows an updated tax calculation.

Sources

This is general information to help you understand the rules. It isn't tailored to your circumstances, so check your own position before acting on it.

Righto Tax is a trading name of NJG Consultancy Ltd, registered in England and Wales, company number 16095900. Registered office: Jubilee House, East Beach, Lytham St Annes, FY8 5FT.

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