Making Tax Digital · Year-end

The final declaration

Making Tax Digital replaces the once-a-year Self Assessment tax return with a final declaration, due 31 January. Here's exactly what it is, what you pay, and how Get Sorted turns it into a 10-minute job.

What is the final declaration?

Under Making Tax Digital (MTD) for Income Tax, you send HMRC four short quarterly updates through the year. Those updates are running totals of your income and expenses — useful, but not your final tax position.

The final declarationis the year-end sign-off where you confirm those figures are complete and correct, add anything that only happens once a year (like your home-office claim or a tweak to a CIS figure), and tell HMRC “this is my tax year, finalised”. It replaces the old Self Assessment tax return for people in MTD.

The deadline is 31 January

Your final declaration for a tax year is due by 31 January after the tax year ends. So for the 2025-26 tax year (which ends 5 April 2026), the deadline is 31 January 2027 — the same date you pay. Miss it and HMRC can charge penalties and interest.

What do you actually pay?

Your bill is made up of income tax and Class 4 National Insurance on your taxable profit, plus any student loan repayment. From that, HMRC takes off any CIS already deducted at source by your contractors — most subcontractors have had more taken than they owe, so they get a refund here rather than a bill.

What's left is your balancing payment — the top-up due on 31 January. If your bill is over £1,000, HMRC also asks for payments on account: two advance payments towards next year, the first on 31 January (alongside the balancing payment) and the second on 31 July.

The year at a glance

Across the yearFour quarterly updates

Under Making Tax Digital you send HMRC a short summary of income and expenses four times a year. These are running totals — not your final bill.

After 5 AprilTax year ends

The tax year closes on 5 April. You now have until the following 31 January to confirm everything and pay.

By 31 JanuaryFinal declaration + payment

You confirm your figures are complete and correct (the final declaration), and pay your balancing payment plus any payment on account. This is the deadline that replaces the old Self Assessment return.

How Get Sorted makes it 10 minutes

1
We track your income and expenses all year, so your four quarterly updates are already done when January comes.
2
A quick readiness check confirms all four quarters are in, your CIS is reconciled, your mileage is logged, and your home-office hours are set.
3
We estimate your bill line by line — taxable profit, income tax, Class 4 NI, student loan, minus CIS — so there are no surprises. (HMRC confirms the exact figure when you declare.)
4
If your bill is over £1,000, we show your payments on account with the exact 31 January and 31 July amounts and dates.
5
Want a second pair of eyes? Have a qualified accountant check your year before you file. Then submit your final declaration to HMRC in a couple of taps.

The figure we show is our estimate

Get Sorted estimates your bill from your own figures and the current tax rates — it's what we expect HMRC to calculate. HMRC confirms the official figure (including the exact CIS credit from your contractors' filings) when you submit your final declaration. If anything looks off, check it with HMRC or a qualified accountant before you declare.

Make January calm

Get Sorted pulls your four quarterly updates together, estimates your bill, and walks you through your final declaration step by step.

Try Get Sorted free →

HMRC sources

gov.uk — Making Tax Digital for Income Tax gov.uk — Understand your Self Assessment tax bill: payments on account

Always verify current thresholds and rates directly with HMRC or a qualified accountant.