HMRC Self Assessment and VAT Deadlines
A calendar of every Self Assessment, VAT and Making Tax Digital date a UK sole trader, freelancer or self-employed person needs to track, plus what happens when one is missed. The page covers the annual Self Assessment cycle, quarterly VAT deadlines, the MTD timeline, late filing and late payment penalties, payments on account, and practical ways to avoid missing a date. It notes that deadlines can change and should be verified with HMRC.
Self Assessment key dates
The Self Assessment calendar follows the same annual cycle every year. The tax year starts on 6 April and ends on 5 April. The second payment on account falls on 31 July. Newly self-employed people must register for Self Assessment by 5 October following the end of the tax year in which they started.
Paper returns are due by 31 October. If you want HMRC to collect a small underpayment through your PAYE code, the online return has to be in by 30 December. The online return and payment deadline is 31 January, which is also when the first payment on account for the following year falls due.
The page describes 31 January as the most important date of the year, because filing and payment land on it together, and missing it triggers penalties automatically.
VAT return deadlines
VAT-registered businesses file quarterly, one calendar month and seven days after the end of the VAT quarter. On standard stagger periods that puts the deadline on the seventh of the second month after the quarter ends.
Under Making Tax Digital all VAT returns must be submitted digitally through MTD-compatible software. If you are on non-standard stagger periods your dates will differ, and you should check them in your HMRC online account.
Payment must reach HMRC by the same date. If you pay by direct debit, HMRC collects roughly three working days after the deadline.
Making Tax Digital deadlines
MTD for VAT is already live: since April 2022 every VAT-registered business, regardless of turnover, must keep digital VAT records and submit through compatible software.
MTD for Income Tax Self Assessment begins in April 2026 for self-employed people and landlords above the first qualifying income band, who will send quarterly updates to HMRC through compatible software instead of only an annual return. The band is lowered in April 2027 and again in April 2028.
The page states that Taxmo is fully MTD-compliant for VAT and is preparing for MTD for Income Tax.
Penalties for late filing and late payment
Late filing penalties for Self Assessment are automatic and apply even if you have no tax to pay or have already paid in full. There is a fixed penalty as soon as the return is late, daily penalties once it is three months late, and further penalties at six months and twelve months, each set as the greater of a flat amount or a percentage of the tax due. In serious cases where HMRC considers information to have been deliberately withheld, the penalty can reach the full amount of the tax due.
Late payment penalties are separate, so filing on time does not protect you if the tax is unpaid. Percentage-based penalties are charged on the tax still outstanding at thirty days, six months and twelve months, and interest runs from the original due date, which makes overdue tax an expensive form of borrowing.
If you cannot pay in full, the page advises contacting HMRC early. A Time to Pay arrangement can spread payments over a period of months, and setting one up early can avoid some penalties.
Payments on account explained
Payments on account are advance payments towards next year's bill. HMRC requires them when your Self Assessment liability exceeds a set amount and most of your tax was not collected at source through PAYE. Each instalment is half of the previous year's total bill.
The first falls on 31 January, at the same time as the balancing payment for the year just filed. The second falls on 31 July. The balancing payment for that year then falls on the following 31 January, covering the difference between what you paid on account and what you actually owed.
If your income has dropped significantly you can apply through your HMRC online account to reduce your payments on account. Reduce them too far and you will be charged interest on the shortfall.
How to avoid missing deadlines
The page offers six practical habits: put every key date in your calendar with reminders at least two weeks ahead, especially for 31 January and 31 July; file early, since you can submit as soon as the tax year ends on 5 April and filing early does not move the payment date; keep records year-round rather than scrambling at the end.
It also suggests setting up direct debit for VAT and using HMRC's Budget Payment Plan for Self Assessment; using MTD-compatible software so digital records make filing faster and reduce errors; and hiring an accountant, who can manage deadlines and find savings that offset their fee. Taxmo is named as the MTD-compatible option for tracking deadlines and record keeping.
Common questions
What happens if I miss the 31 January Self Assessment deadline?
You get an automatic fixed penalty straight away, even if you have no tax to pay. Daily penalties start once the return is three months late, and further penalties apply at six and twelve months. Interest also runs on any unpaid tax from the due date. Filing late is always better than not filing, because the penalties keep accumulating the longer you leave it.
Do I need to make payments on account?
You need to make payments on account if your Self Assessment bill exceeds a set amount and less than most of your tax was collected at source through PAYE. Each payment is half of your previous year's bill, with the first due on 31 January and the second on 31 July. If your income has dropped you can apply to HMRC to reduce them, but interest is charged if you reduce them too far and underpay.
When are VAT returns due under Making Tax Digital?
VAT returns must be submitted digitally through compatible software within one calendar month and seven days of the end of each VAT quarter. For businesses on standard quarterly periods that puts the deadline on the seventh of the second month after the quarter ends. Making Tax Digital changed the method, not the timing, so the deadlines are the same as before.
Can I change my Self Assessment deadline by changing my accounting period?
No. The Self Assessment deadline is fixed at 31 January following the end of the tax year on 5 April. You can choose different accounting dates for your business, which affects which tax year some income falls into, but the tax year itself always runs 6 April to 5 April, and since the basis period reform all businesses are taxed on the tax year basis.
What is the penalty for late VAT returns?
HMRC uses a points-based system introduced in January 2023. Each late submission earns one penalty point, and once you reach the threshold for your filing frequency a fixed financial penalty applies for that return and every subsequent late one. Points expire after a period of full compliance. Late payment penalties are separate and are charged as percentages of the tax still outstanding.
How do I register for Self Assessment if I am newly self-employed?
Register with HMRC by 5 October following the end of the tax year in which you became self-employed. You do this online through the HMRC website, and you will receive a Unique Taxpayer Reference by post, usually within a couple of weeks and longer if you are abroad. You also need a Government Gateway account. Once registered you must file a return every year, even in a year you made a loss, until you formally deregister.