How to Pay Your Self Assessment Tax Bill: Deadlines, Methods and Payment Plans

Self Assessment tax is due by 31 January following the end of the tax year, with a second payment on account by 31 July. You pay HMRC using your 10-digit UTR followed by the letter K as the reference, and the fastest methods are online banking, the HMRC app or a debit card, all of which can arrive the same day. If you cannot pay in full, a Time to Pay arrangement can usually be set up online in a few minutes. This guide covers the deadlines, every payment method, and what late payment costs.

When Self Assessment tax is due

• 31 January: the balancing payment for the tax year that ended the previous April, plus the first payment on account for the current year.
• 31 July: the second payment on account.

So for the 2025/26 tax year, the balance is due on 31 January 2027, and if payments on account apply, half of next year's estimated bill is due the same day with the other half on 31 July 2027. Our guide to payments on account explains how those are calculated. If the deadline falls on a weekend, pay by the previous working day so the money arrives in time.

Your payment reference

Every Self Assessment payment uses the same reference: your UTR followed by K, for example 1234567890K. No spaces, no other letters. HMRC's bank details for Faster Payments, CHAPS and Bacs are published on GOV.UK; use the account for Self Assessment (HMRC Cumbernauld), not the one for Corporation Tax or VAT.

Ways to pay and how long they take

• Online or mobile banking (Faster Payments): same day or next day, free, available every day.
• HMRC app or "pay now" on GOV.UK: takes you to your own bank through open banking, with the reference filled in. Same day.
• Debit card online: same day, free. Corporate credit cards are accepted with a fee; personal credit cards are not.
• CHAPS: same day if sent before your bank's cut-off, but your bank may charge.
• Bacs: three working days.
• Direct Debit: set up in your HMRC account. Allow five working days the first time, three after that. Each payment must be set up individually unless you use a budget payment plan.
• At your bank or building society: only with an HMRC paying-in slip, same or next day.
• Cheque by post: allow at least three working days, and write your UTR with K on the back.

HMRC no longer accepts payment at the Post Office.

If you cannot pay in full: Time to Pay

If you cannot pay the full amount by the deadline, set up a Time to Pay arrangement rather than waiting to be chased. You can do it online, without speaking to anyone, if you:

• Owe £30,000 or less.
• Have filed the return the debt relates to.
• Are within 60 days of the payment deadline.
• Have no other payment plans or debts with HMRC.

You choose the monthly amount and the plan runs for up to twelve months. For larger amounts, or if you are already outside the window, call the Self Assessment payment helpline with a realistic proposal of what you can afford. Interest continues throughout, but late payment penalties do not apply while the plan is kept to.

Paying in advance with a budget payment plan

If January bills are a shock every year, a budget payment plan lets you pay HMRC a fixed amount by Direct Debit every week or month towards your next bill. You set the amount, can change or pause it, and the credit simply reduces what is due on 31 January. It is set up from the Direct Debit section of your online account and only works if you are up to date with previous payments.

Interest and penalties for paying late

• Interest runs daily from the due date at the Bank of England base rate plus 4 percentage points, on the unpaid amount, until it is paid.
• 5% penalty on tax still unpaid 30 days after the deadline (so from 2 March for a 31 January bill).
• A further 5% on tax still unpaid at six months, and another 5% at twelve months.

These are separate from late filing penalties, which start at £100 the day after the filing deadline whether or not any tax is due. A Time to Pay arrangement agreed before the 30-day point stops the payment penalties but not the interest.

Checking your payment has arrived

Your Self Assessment statement in the HMRC app or online account updates within a few days of a payment. If a payment is missing after a week, the most common cause is a wrong reference. Have your bank's confirmation ready and call HMRC with the amount, date and reference used; they can trace and reallocate it.

What Cloudkeepers can do

When we prepare your return we tell you exactly what is due, when, and with which reference, and we remind you before both deadlines. If a bill is going to be difficult, say so early: we can reduce payments on account where that is justified and help you put a payment plan in place. See our Self Assessment service.