Paying your 31 January 2027 Self Assessment tax bill

acrenvo.com/guides/paying-your-january-2027-tax-bill, last reviewed 25 October 2026

The Self Assessment bill for the 2025 to 2026 tax year is due on 31 January 2027. For most people it is two amounts added together: whatever is still owed for 2025 to 2026, and the first payment on account towards the following year. The second payment on account follows on 31 July 2027.

Owen is fictional, but his January will be familiar to many people in the first group to join Making Tax Digital (MTD) for Income Tax. He is a self-employed plumber who also lets a flat, and he has been sending quarterly updates since 6 April 2026. His accountant has reminded him that a Self Assessment bill is due on 31 January 2027, and he wants to know what it covers, whether he can pay it in parts, and whether the new MTD penalties he keeps reading about would apply if he paid late. This guide follows his questions, using GOV.UK’s own words for every rule.

If you are not in MTD for Income Tax yet, the return behind this bill may matter to you in another way. GOV.UK says that if your qualifying income for the 2025 to 2026 tax year was over £30,000, you will need to use MTD for Income Tax from 6 April 2027. Its guidance on if and when you need to use it explains that “HMRC will review your Self Assessment tax return and check your qualifying income each tax year.” The 2025 to 2026 return is the one HMRC will read for that step. The guide to MTD from April 2027 explains what joining involves, and the threshold calculator gives a quick first check against your own figures.

What is due on 31 January 2027

The bill Owen pays in January belongs to the 2025 to 2026 tax year, the last year before MTD started for him. GOV.UK’s page on paying your Self Assessment bill says that the deadlines for paying your tax bill are usually:

So for most people the January payment is two amounts added together: whatever is still owed for 2025 to 2026, and the first payment towards the following year. GOV.UK’s payments on account page explains that ‘Payments on account’ are payments towards your next tax bill (including Class 4 National Insurance if you’re self-employed). They help spread the cost of your tax by making payments in 2 instalments. Each payment is half of the tax you owed last year.

What Owen pays depends on whether he made payments on account last year, and GOV.UK covers both cases: If you made payments on account last year, you’ll need to pay both your first payment on account towards your next bill and any balancing payment you owe (if you still have tax to pay after last year’s 2 payments on account). If you did not make any payments on account last year (for example, because it’s your first time filing Self Assessment) you’ll need to pay both the full amount of your tax calculation and your first payment on account towards your next bill. Either way, your Self Assessment statement or online account will show you how much they are, if you need to pay them.

Not everyone has to make payments on account. GOV.UK says that you must make these 2 payments, unless either the amount of tax you owed last year was less than £1,000 or last year you paid more than 80% of the tax you owed outside of Self Assessment (for example through your tax code or because your bank had already deducted interest on your savings).

Make sure you pay HM Revenue and Customs (HMRC) by the deadline. You’ll be charged interest and may be charged a penalty if your payment is late. The time you need to allow depends on how you pay. If the deadline falls on a weekend or bank holiday, make sure your payment reaches HMRC on the last working day before (unless you’re paying by Faster Payments or by debit or credit card). 31 January 2027 falls on a Sunday, so that rule is worth keeping in mind for this bill. Online payment services may be slow during busy times. HMRC lists any current problems on its Self Assessment: service availability and issues page.

Why the second payment on account falls on 31 July 2027

Payments on account come in pairs, and the first of each pair is part of the January bill. GOV.UK gives 31 January and 31 July as the dates, so Owen’s second payment towards his 2026 to 2027 bill falls on 31 July 2027. That day is a Saturday, so the weekend rule above is worth bearing in mind for this payment too. It is easy to forget once January is over, so it helps to plan for it now rather than finding it on a statement in the summer.

If Owen expects his tax for 2026 to 2027 to be lower, he has a choice. If you know the tax you owe is going to be lower than last year, you can ask HM Revenue and Customs (HMRC) to reduce your payments on account. You can do this either online or by post. You will need to include the amount you expect to make so HMRC can use this to work out your new payments on account. GOV.UK sets out the steps for doing it online:

1. Sign in to your online account.
2. Select the option to view your latest Self Assessment return.
3. Select ‘Reduce payments on account’.

By post, GOV.UK’s instruction is “Send form SA303 to your tax office.” It also adds a caution: if you reduce your payments on account and your tax bill is higher than expected, you’ll be charged interest on the difference.

Spreading the cost before the deadline

You can pay the amount you owe in instalments before the deadline, if you prefer. One way GOV.UK describes is a Budget Payment Plan, set out on its page on paying weekly or monthly. You can set up a Budget Payment plan to make weekly or monthly Direct Debit payments towards your next Self Assessment tax bill. Your payments will be used against your next tax bill - this means you’ll have less to pay at the payment deadline.

Owen needs to meet one condition before he starts, and it is easy to miss. To set up a plan you must be up to date with any payments from your last Self Assessment tax bill. Once a plan is running, if the amount you’ve paid does not cover all of your next bill, you’ll need to pay the difference. If you’re in credit, you can ask for a refund. You can pause payments for up to 6 months if you need to.

Paying through your tax code

Owen has no salary or pension, so this route is not open to him, but it can be for anyone who has a job alongside self-employment or letting. GOV.UK’s page on paying through your tax code says that you can pay your Self Assessment bill through your PAYE tax code as long as all these apply:

• you owe less than £3,000 on your tax bill (you cannot make a part payment to meet this threshold)
• you already pay tax through PAYE, for example you’re an employee or you get a company pension
• you submitted your paper tax return by 31 October or your online tax return online by 30 December

HM Revenue and Customs (HMRC) will automatically collect what you owe through your tax code if you meet all 3 conditions, unless you’ve specifically asked them not to (on your tax return). If you’re not eligible, you will not be able to pay this way. For the 2025 to 2026 return that goes with this bill, the online date in that list falls this December, so it is worth filing in good time if you would like to pay this way.

GOV.UK also says when the route is closed, even for someone with Pay As You Earn (PAYE) income. You will not be able to pay your tax bill through your PAYE tax code if:

• you do not have enough PAYE income for HMRC to collect it
• you’d pay more than 50% of your PAYE income in tax
• you’d end up paying more than twice as much tax as you normally do
• you owed £3,000 or more but made a part payment to reduce the amount you owe to less than £3,000

One email a month lists the MTD software price changes we have checked and any changes to HMRC’s list of software. If that would be useful, you can sign up for the monthly price-changes email at the end of this page.

If you cannot pay

If January arrives and Owen cannot pay the whole bill, GOV.UK’s advice changes. If you’ve missed your Self Assessment payment deadline or you cannot pay the amount you owe, you might be able to set up a payment plan (also known as a ‘Time to Pay’ arrangement). Its page on what to do if you cannot pay your tax bill on time says that if you cannot pay your tax bill in full, you may be able to set up a payment plan to pay it in instalments. HM Revenue and Customs (HMRC) will check if a payment plan is affordable for you. If you cannot agree a payment plan with them, they’ll ask you to pay the amount you owe in full.

The page on paying in instalments draws the line between the two kinds of plan. You may be able to set up a payment plan to pay your overdue tax bill in monthly instalments. If your bill is not overdue and you want to make weekly or monthly payments towards your next Self Assessment tax bill, you may be able to set up a Budget Payment Plan instead. It also says that if you have savings or assets, HMRC will expect you to use these to reduce your debt as much as possible. The same page lists what HMRC will ask for when you set a plan up, so it is worth reading before you call or apply.

Which penalties apply to the 2025 to 2026 tax

Owen has spent months reading about MTD’s new penalty points and late payment percentages, so it is natural for him to assume they cover this bill too. GOV.UK’s MTD penalties page says that changes to late submission penalties and late payment penalties will apply to you from the tax year you join Making Tax Digital for Income Tax. It then addresses his exact situation:

That means the bill for 2025 to 2026 is under the current Self Assessment penalties, not the new MTD ones. GOV.UK’s Self Assessment penalties page sets out the current steps for paying late:

Sending the return late is a separate matter from paying late, and the same page gives it its own steps. If Owen’s return for the 2025 to 2026 tax year went in after 31 January 2027, GOV.UK says:

If you have a reasonable excuse, you can appeal against a penalty. The new MTD rules, which the guide to MTD penalties explains, start from the tax year Owen joined rather than from the year this bill belongs to. Once they apply to him, the MTD penalty estimator can show what a missed deadline or a late payment would cost under them.

HMRC’s own pages on paying

Each of these GOV.UK pages is worth reading in full before paying, since they are where any change would appear first.

• Pay your Self Assessment tax bill
• Pay your Self Assessment tax bill weekly or monthly
• Payments on account
• Pay your tax bill in instalments
• Self Assessment tax returns, penalties
• Penalties for MTD for Income Tax

The return that goes with this bill is covered in MTD and your January Self Assessment return.

Questions people ask about the January bill