What you owe on 31 January 2027

1. The balancing payment for 2025/26

The balancing payment settles your 2025/26 tax year, which ran from 6 April 2025 to 5 April 2026. HMRC works it out by taking the total tax you owe for the year (income tax and Class 4 National Insurance) and deducting any payments on account you have already made. It is due by midnight on 31 January 2027, the same day as the online return.

2. The first payment on account for 2026/27

Payments on account are advance payments towards next year's bill. There are two, and each is usually half of the Self Assessment bill you owed for the previous year, Class 4 National Insurance included. For 2026/27 that means half of your 2025/26 bill. The first falls due on 31 January 2027, so it lands on top of the balancing payment.

3. When payments on account apply

You do not have to make them if either of these is true:

• your 2025/26 Self Assessment bill was under £1,000, or
• you paid more than 80% of your 2025/26 tax outside Self Assessment, for example through your tax code.

If neither applies, expect them. If this is your first year in Self Assessment, you have not paid on account before, so the January bill is the full balancing payment plus the first payment on account.

4. The second payment, due 31 July 2027

The second payment on account is the other half of the same amount. It is due by midnight on 31 July 2027, so put it aside from February onwards rather than waiting for the summer.

A worked example

Say your 2025/26 bill comes to £8,000. In 2025/26 you paid two payments on account of £3,000 each, because your 2024/25 bill was £6,000.

On 31 July 2027 you then pay a second payment on account of £4,000. If you had not paid on account before, the January bill would be £8,000 plus £4,000, so £12,000.

These round numbers show how the sums fit together. Your own figures depend on your income, so use the payments on account calculator.

Late filing and late payment

• Late return: an automatic £100 penalty if your 2025/26 online return is not in by 31 January 2027. Further charges build up the longer it is outstanding, starting with £10 a day after three months, up to £900.
• Late payment: 5% of the tax still unpaid at 30 days, again at 6 months and again at 12 months, plus interest on the amount owed.

If your income has fallen

If you expect a smaller bill for 2026/27, you can reduce your payments on account online or by sending form SA303 to HMRC; if the bill turns out higher than you said, you are charged interest on the difference.