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Self Assessment payment on account deadline: key dates
Self Assessment payments on account fall due twice a year, on 31 January and 31 July. The 31 January date also carries the balancing payment for the previous tax year. Both payments must be made by midnight on the due date, and when the money reaches HMRC depends on the payment method and on whether the deadline falls on a weekend or bank holiday.
What each deadline covers
| Deadline | What it covers |
|---|---|
| 31 January | The balancing payment for the previous tax year, plus the first payment on account |
| 31 July | The second payment on account |
If your actual tax for the year is higher than the payments on account, the balancing payment is due by midnight on the following 31 January.
Weekend and bank holiday rule
If a deadline falls on a weekend or bank holiday, the payment should reach HMRC by the last working day before it. This does not apply to Faster Payments or to debit or credit card payments.
Processing times by payment method
Arrival time depends on the method used, so allow for the processing time when scheduling a payment.
| Payment method | Time to reach HMRC |
|---|---|
| Faster Payments | Same or next day |
| CHAPS | Same or next day |
| Online bank transfer | Same or next day |
| Debit card | Same or next day |
| Bacs, or a Direct Debit already set up with HMRC | 3 working days |
| New Direct Debit | 5 working days |
For a new Direct Debit, the five working days run from when it is set up, so a first payment needs to be scheduled well before the deadline. Bacs and existing Direct Debits take three working days to arrive.
Source: GOV.UK (HMRC), 2026.
What is a payment on account?
A payment on account is an advance instalment towards your Self Assessment tax bill, including Class 4 NIC where it applies, for the current tax year. Each one is based on your previous year’s bill. It is paid before that bill is final, and HMRC credits it against the amount you owe once the return is processed. It is not an extra charge on top of your tax. Its purpose is to spread part of the tax you expect to owe across the year, so the final payment is smaller.
If your actual tax is higher than the payments on account, you pay the difference as a balancing payment by midnight on the following 31 January. If the payments on account cover the full bill, no balancing payment is needed.
How much is each payment on account?
Each payment on account is usually 50% of the previous year’s tax bill. For self-employed people, that bill includes Class 4 National Insurance contributions paid through Self Assessment, so the calculation uses the combined total where it applies.
The rule works as a single calculation:
Usual payment on account = 50% x previous year’s bill (Income Tax, plus Class 4 NIC where it applies)
Because there are two payments on account each year, each one is the same amount. Together they equal the previous year’s bill, paid in advance. This is the default basis, and you can ask HMRC to reduce it if you expect a lower bill.
To find the base, open your most recent Self Assessment return in your HMRC online account and check the total tax due, including Class 4 NIC. Halve that figure to get each payment.
Worked example (illustrative arithmetic): if the previous year’s bill was £6,000, including Class 4 NIC, the calculation is £6,000 x 50% = £3,000 for each payment.
| Item | Amount |
|---|---|
| Previous year’s bill (Income Tax + Class 4 NIC) | £6,000 |
| Each payment on account (50%) | £3,000 |
| First payment on account, due by midnight on 31 January | £3,000 |
| Second payment on account, due by midnight on 31 July | £3,000 |
Source: GOV.UK (HMRC), 2026.
Do I have to make payments on account?
You do not need to make payments on account if either of two conditions applies, both judged on last year’s tax. The first is that last year’s bill was under £1,000. The second is that more than 80% of last year’s tax was paid outside Self Assessment, for example through your tax code. If either condition is met, the 31 January and 31 July payments on account do not apply to you.
The second test covers people whose tax is mostly collected at source. A typical case is an employee whose salary is taxed through PAYE, where the tax code determines how much income tax is deducted each month. If most of last year’s tax came through that route, the 80% threshold may be met even though you also file a Self Assessment return. The test looks at the share of last year’s tax paid outside Self Assessment, which must be more than 80%.
Both conditions depend on figures you can confirm from your most recent return, which shows your total tax bill and the amount settled outside Self Assessment. Compare those two numbers directly against the £1,000 limit and the 80% threshold before deciding whether payments on account apply.
Can I reduce my payments on account?
Payments on account are advance instalments of your next Self Assessment bill, usually based on last year’s tax. If you expect your bill for the current year to be lower, you can ask HMRC to reduce them. This is useful when you expect a lower bill, because the default instalments would then be higher than the tax you are likely to owe.
Online route, the faster method:
- Sign in to your Self Assessment account on GOV.UK.
- Open your latest return.
- Choose ‘Reduce payments on account’.
- Enter the reduced amounts and submit.
Postal route: send form SA303 to HMRC. This is the alternative to the online request.
What a reduction changes: the instalment amounts. The payment dates stay the same, with the first payment due on 31 January and the second on 31 July. If your final bill turns out higher than expected, you pay interest on the difference.
What a reduction does not change: the final tax bill. That bill is calculated from your actual income and expenses in your return, so a reduced instalment does not lower the amount you owe overall. Any difference between your instalments and your actual tax is settled in the balancing payment.
What happens if I pay late?
A late Self Assessment payment brings interest, and a penalty may also apply, according to GOV.UK (HMRC, 2026). Each payment is due by midnight on its deadline, so any amount that has not reached HMRC by then is treated as late and the consequences below can apply.
The weekend and bank holiday rule explained above also applies to late payment.
Interest on late payments
Interest applies to a payment that arrives after its due date. Check the current figures on GOV.UK before estimating what a late payment would cost.
Interest can also apply without a late payment in one specific case. If your final tax bill is higher than the payments on account you made, you pay interest on the difference.
Penalties
A penalty may be charged in addition to interest. The verified source confirms only that a penalty is possible. It does not state the amount, when it starts, or whether extra charges are added over time. Use the official HMRC guidance for those details rather than estimates from this article.
How can I spread the cost?
Spreading a payment on account means moving part of the bill out of the two lump-sum deadlines and into smaller amounts paid beforehand. Only the advance payments option comes from HMRC. The other two ideas are personal budgeting approaches. HMRC allows you to pay in advance through weekly or monthly payments, so the money can reach HMRC before 31 January or 31 July instead of all at once on those dates.
Three methods fit this approach:
- Advance weekly or monthly payments: Arrange regular amounts paid to HMRC ahead of each deadline. Each payment reduces the amount still owed when the deadline arrives.
- A fixed monthly set-aside: Each time you receive income, move the same fixed sum into a separate account and leave it there until the deadline. A constant amount makes the total you have built up easy to predict.
- Planning against the two deadline totals: Identify what is due on 31 January and what is due on 31 July, then count the weeks or months left before each date. Dividing each target by that count gives the regular amount to set aside.
Working backwards from the two deadlines keeps each target fixed, so you can see early whether your savings are on track.
If you expect a lower bill, you can ask to reduce your payments on account, as explained above. This lowers the target you need to save toward.
Frequently asked questions
Do I have to make payments on account every year?
Not always. You can skip them if last year’s Self Assessment bill was under £1,000, or if more than 80% of last year’s tax was paid outside Self Assessment, such as through your tax code.
What if I reduce my payments on account and my final bill is higher?
You will owe interest on the difference between what you paid during the year and your actual tax. To lower the payments, sign in online, open your latest return and choose ‘Reduce payments on account’, or post form SA303.
What happens if I miss a payment on account deadline?
Late payment can trigger a penalty in addition to interest. If you want to avoid a lump sum, you can instead pay ahead through weekly or monthly payments.
