Self Assessment · payments on account

Your 31 July payment on account

If you're a sole trader or landlord who pays tax twice a year, this is the second instalment. Work out how much is due, check whether you're actually exempt, and see how to apply to pay less — properly, not by guessing.

How much is due?

Quickest answer: if you made a payment on account on 31 January, this one is normally the exact same amount — check your HMRC online account or last statement. Otherwise, work it out here.

Your total Self Assessment tax bill for the year before last Income Tax + Class 4 National Insurance only — not Capital Gains Tax, not Class 2, not student loan

More than 80% of that bill was already collected some other way — e.g. through your PAYE tax code, or tax deducted from bank interest

Can I pay less than that?

Yes — if you genuinely expect this year's profit to be lower, you can apply to reduce your payments on account. Do it online through your Self Assessment account (the quickest way), or by post using form SA303. You'll need a realistic estimate of this year's tax bill, which is exactly what our free tax calculator is for — run your current-year numbers through it first, so the figure you give HMRC is one you can actually stand behind.

Reduce too far and it costs you

If your real bill ends up higher than the reduced amount you claimed, HMRC charges interest on the shortfall from the day it was due — there's no penalty on a payment on account itself, just interest, but it accrues daily and adds up. The rate moves with the Bank of England base rate (it was 7.75% as of the last published update, 9 January 2026) — check the current HMRC rate before deciding how far to reduce.

The rules in short

Two instalments a year: 31 January and 31 July
Each is normally half of last year's Income Tax + Class 4 NIC liability
You're exempt if last year's relevant bill was under £1,000, or if 80%+ of it was already collected another way
Any balance still owed after both instalments is due as a "balancing payment" the following 31 January
A reduction claim can be made any time — before or after a payment is due — but do it before 31 July to avoid paying more than you need to now

More free tools

Estimate this year's bill →Get a realistic figure before you claim a reduction. Am I in MTD? →Check your qualifying income and start date in 20 seconds. MTD deadlines →See every quarterly update date and add them to your calendar.

Know the number before HMRC tells you

A payment on account shouldn't be a surprise. Our tax estimator works out your current-year liability — and your set-aside — so the next 31 January or 31 July is a formality, not a scramble.

Self Assessment Tax Estimator 2026/27 — know what you owe before January, not after.
Rental Property ROI & Yield Calculator — including Section 24 and a rate stress test.
Freelance Day-Rate & Profit Calculator — works backwards from the take-home you want.
Invoice Tracker & Log — auto paid/outstanding/overdue, with a chase list.

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