Key takeaways
- Tax owed for the 2025/26 tax year must be paid by 11:59pm on 31 January 2027.
- Payments on account for 2026/27 are due by 31 January 2027 and 31 July 2027, each normally half of your 2025/26 bill.
- You do not make payments on account if last year's bill was under £1,000 or more than 80% of your tax was paid at source.
- A first-year sole trader with £45,000 profit owes £8,431.80 for 2025/26 and pays £12,647.70 on 31 January 2027.
- Bills under £3,000 can be collected through your PAYE tax code if you file online by 30 December 2026.
You need to pay the Self Assessment tax you owe for the 2025/26 tax year by 11:59pm on 31 January 2027. If you have to make payments on account, the first one for 2026/27 is due on that same day and the second by 31 July 2027.
Those two dates, 31 January and 31 July, are the Self Assessment payment deadlines every year. What you pay on each date depends on whether it is your first year in Self Assessment and whether HMRC asks you for payments on account.
Self Assessment payment dates for the 2025/26 bill
| Deadline | What you pay |
|---|---|
| 30 December 2026 | Not a payment date, but the last day to file online if you want a bill under £3,000 collected through your PAYE tax code |
| 31 January 2027 | Any tax still owed for 2025/26 (the balancing payment), plus the first payment on account for 2026/27 if one is due |
| 31 July 2027 | The second payment on account for 2026/27 |
| 31 January 2028 | Any balancing payment for 2026/27, plus the first payment on account for 2027/28 |
Each deadline is 11:59pm on the day. HMRC must receive your payment by then, so allow for the time your payment method takes. Sources: GOV.UK Self Assessment deadlines and Pay your Self Assessment tax bill.
What the balancing payment is
The balancing payment is whatever you still owe for the tax year once any payments on account you have already made are taken off. HMRC works it out by deducting the payments on account from the total tax on your return. It also includes anything you owe for Capital Gains Tax and, if you are self-employed, student loan repayments. It is due by 31 January after the end of the tax year.
If you paid more on account than your final bill, you do not have a balancing payment. You may be able to claim the difference back, or leave it on your account towards the next payment.
Payments on account: who has to make them
Payments on account are advance payments towards your next tax bill, including Class 4 National Insurance if you are self-employed. There are two of them, due by 31 January and 31 July, and each one is normally half of the tax you owed for the previous year.
You must make them unless either of these applies:
- your Self Assessment bill for the previous year was less than £1,000
- you paid more than 80% of the tax you owed for the previous year outside Self Assessment, for example through your tax code or because your bank had already deducted tax on savings interest
If you expect this year's tax to be lower than last year's, you can ask HMRC to reduce your payments on account, online or on form SA303. If you reduce them too far and the final bill is higher, HMRC charges interest on the difference. Our guide to Self Assessment payments on account covers this in more detail.
Worked example: your first year in Self Assessment
The first January bill is the one that catches people out, because it covers a whole year's tax plus half of the next year's in advance. Take a sole trader in England who started trading in 2025/26, made £45,000 of profit and had no other income.
| Item | Calculation | Amount |
|---|---|---|
| Income Tax | (£45,000 less the £12,570 Personal Allowance) at 20% | £6,486.00 |
| Class 4 National Insurance | 6% of profits between £12,570 and £45,000 | £1,945.80 |
| 2025/26 tax bill | Income Tax plus Class 4 | £8,431.80 |
| First payment on account for 2026/27 | Half of £8,431.80 | £4,215.90 |
| Due 31 January 2027 | £8,431.80 plus £4,215.90 | £12,647.70 |
| Due 31 July 2027 | Second payment on account | £4,215.90 |
So in the space of six months this person pays £16,863.60: the full 2025/26 bill plus £8,431.80 towards 2026/27. If their 2026/27 bill turns out to be exactly £8,431.80 again, nothing more is due for that year on 31 January 2028 apart from the first payment on account for 2027/28. If it comes to £9,000, they owe a balancing payment of £568.20 on 31 January 2028, plus a first payment on account of £4,500 for 2027/28.
To estimate your own figures, try our self-employed tax calculator.
Paying through your tax code instead
If you are also employed or get a pension, HMRC can collect your Self Assessment bill through your PAYE tax code, so the tax comes out of your pay or pension in equal instalments over 12 months. All of these must apply:
- you owe less than £3,000 on your tax bill, and you did not get under £3,000 by making a part payment
- you already pay tax through PAYE
- you filed a paper return by 31 October or an online return by 30 December (30 December 2026 for 2025/26 returns)
HMRC sets this up automatically if you qualify, unless you ask it not to on your return. It will not collect this way if you do not have enough PAYE income, if you would pay more than 50% of your PAYE income in tax, or if you would pay more than twice as much tax as you normally do. Source: GOV.UK.
How to pay
You can pay online, through the HMRC app, by bank transfer, by Direct Debit, by personal debit card, or by cheque. Some methods reach HMRC the same or next day, while Bacs takes 3 working days and a first Direct Debit 5 working days. You will need your 11-character payment reference, which is your 10-digit UTR followed by the letter K. Our guide on how to pay your Self Assessment tax walks through each method, and you can find your UTR here.
If you would rather not face one large bill, you can pay towards it in advance, including weekly or monthly through a Budget Payment Plan. See how to pay HMRC early.
What happens if you pay late
HMRC charges interest on tax paid after the deadline, and late payment penalties of 5% of the tax unpaid at 30 days, 6 months and 12 months. These are separate from the penalties for filing your return late (GOV.UK penalties).
If you cannot pay in full, contact HMRC before the deadline if you can. You may be able to set up a payment plan to pay what you owe in monthly instalments, and there is no fixed time limit on how long one can last (GOV.UK).
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