Your payment timeline
| Due date | What it's for | Amount |
|---|---|---|
| Enter your numbers above to see this table. | ||
How to use this calculator
- Enter your Self Assessment bill for 2025 to 2026: the Income Tax and Class 4 National Insurance you owe through your tax return.
- Enter any payments on account you've already made for that year. In your first year this is 0.
- Enter tax taken at source, such as PAYE, which decides whether you need payments on account at all.
- Optionally estimate this year's bill to see what's due in January 2028.
How it's calculated
Worked example: the first-year shock
Tom started freelancing in 2025 to 2026 and his first Self Assessment bill is £8,000. He hasn't made any payments on account, and he expects to owe £9,000 for 2026 to 2027.
Tom must pay £12,000 in January 2027, one and a half times his first year's bill, so it pays to start saving early.
What this calculator doesn't cover
- Student loan repayments and Capital Gains Tax, which aren't included in payments on account.
- Interest or penalties on late payments.
- Reducing payments on account, which you do through your HMRC online account or form SA303.
Frequently asked questions
What are payments on account?
Advance payments towards your next tax bill, each worth half of last year's bill. They're due by 31 January and 31 July, and include Class 4 National Insurance if you're self-employed.
Do I have to make payments on account?
Not if your last Self Assessment bill was under £1,000, or if more than 80% of the tax you owed was already taken at source, for example through PAYE.
Can I reduce them?
Yes, if you expect to earn less this year. But if you reduce them too far, HMRC charges interest on the difference.
Source: GOV.UK: payments on account.