A missed filing date can turn a manageable admin task into a fine, interest charge or a difficult conversation with HMRC. For many business owners, accounting deadlines become stressful not because the work is especially complicated, but because information has been left until the last minute. A clear timetable gives you more control over cash flow, reduces disruption and protects the peace of mind that comes from knowing your compliance is handled.
The dates that apply to you depend on your business structure, year end, VAT registration and whether you employ people. The guide below covers the main UK deadlines that sole traders, limited companies, landlords and employers should keep firmly on their calendar.
Why accounting deadlines deserve a cash flow plan
Deadlines are not simply paperwork dates. Several require a payment as well as a return, and the money may be due before you have received payment from your own customers. Corporation Tax, VAT, PAYE and Self Assessment can therefore put pressure on working capital when they are not planned for.
Good bookkeeping changes the picture. When sales, costs, payroll and bank transactions are kept up to date, you can see a likely tax position well before the return is due. That creates time to set funds aside, check that reliefs and allowable expenses have been considered, and correct any gaps in the records. It also allows your accountant to advise proactively rather than working under unnecessary time pressure.
The key accounting deadlines for UK businesses
Limited company accounts and Corporation Tax
A private limited company normally needs to file annual accounts with Companies House nine months after its financial year end. The deadline is different for a company’s first accounts, which are usually due 21 months after incorporation, although the exact date should always be checked on the Companies House register.
Corporation Tax follows a separate timetable. Your company must usually pay its Corporation Tax nine months and one day after the end of its accounting period. The Company Tax Return is generally due 12 months after that period ends. This difference catches out many directors: filing the return later does not mean you can pay the tax later.
For example, a company with a 31 March year end will usually need to pay Corporation Tax by 1 January and file its return by the following 31 March. Larger companies or businesses with unusually long accounting periods can have different payment arrangements, so tailored advice is worthwhile where circumstances are more complex.
A limited company must also file a confirmation statement at least every 12 months. It is due within 14 days of the end of the relevant review period. Keep details of directors, shareholders, people with significant control and registered office information current rather than treating this as an afterthought.
VAT return deadlines
Most VAT-registered businesses submit returns online and pay any VAT due one month and seven days after the end of each accounting period. Quarterly returns are common, but some businesses use monthly returns or the Annual Accounting Scheme. The deadline shown in your VAT online account is the one to follow.
The practical issue is often not submitting the return. It is having accurate records of sales VAT, purchase VAT, imports, receipts and invoices ready in time. Making Tax Digital requires most VAT-registered businesses to maintain digital records and submit through compatible software. Regular bookkeeping means your VAT figure is visible during the quarter, rather than arriving as an unwelcome surprise a few days before payment is due.
PAYE and payroll deadlines
If you run payroll, you must report pay, tax, National Insurance and other deductions to HMRC on or before each payday through a Full Payment Submission. This applies even where a member of staff is paid only occasionally.
PAYE and National Insurance payments are normally due by the 22nd of the following tax month when paid electronically. The deadline is the 19th for postal payments. Smaller employers who qualify to pay quarterly have a different timetable, but they still need to submit payroll reports on time.
At the end of the tax year, the final payroll submission should be made by 5 April. Employees must receive their P60 by 31 May. If you provide taxable benefits, P11D forms are generally due by 6 July, with any Class 1A National Insurance payable by 22 July when paid electronically.
Self Assessment deadlines for sole traders and landlords
The Self Assessment tax year runs from 6 April to 5 April. Paper tax returns must usually reach HMRC by 31 October following the end of the tax year. For online returns, the usual filing deadline is 31 January.
Any balancing payment for the previous tax year is also due by 31 January. If payments on account apply, the first instalment is paid on the same date and the second is due by 31 July. Payments on account are often a source of frustration for newly profitable sole traders and landlords because they advance part of the following year’s bill. They are estimates, however, and may be reduced where income is genuinely expected to fall.
If you have not filed before, register for Self Assessment early. The registration process has its own lead time, and leaving it until January rarely creates the calm, informed decision-making that good tax planning requires.
Build a deadline process that works in real life
A calendar is helpful, but it is not enough on its own. The strongest process works backwards from each statutory deadline and includes time for the work that must happen first. For a VAT return, that means reconciling the bank, raising missing sales invoices, collecting supplier receipts and reviewing the figures before submission. For year-end accounts, it may mean confirming stock, chasing information on loans or finance agreements, and checking director transactions.
Start by recording every deadline that applies to your business, including the payment date as well as the filing date. Then set an internal deadline at least two weeks earlier. This buffer is especially valuable when a key person is on holiday, a software feed fails or you need to clarify a transaction.
Set aside tax funds as you trade rather than trying to find a large sum at the deadline. The right percentage depends on profitability, drawings, VAT status, employment costs and other factors, so a generic rule is not always reliable. A separate tax savings account can make the discipline easier and gives a clearer view of the cash genuinely available to spend.
Finally, review your records monthly. For a small business, a short monthly finance routine is usually more effective than a major quarterly catch-up. It keeps the bank reconciled, highlights overdue customer payments and gives a current picture of margins and cash flow. Those are management benefits as well as compliance benefits.
What happens if a deadline is missed?
The consequences vary by obligation. Companies House can charge automatic late filing penalties for accounts. HMRC may charge late filing penalties, interest on overdue tax and, in some cases, further penalties if delays continue. Repeated issues can also damage your ability to obtain finance, as lenders and suppliers may review filed accounts and public company information.
If you have missed a deadline, act promptly. File outstanding returns as soon as possible, pay what you can and seek advice before ignoring HMRC correspondence. Where there is a reasonable excuse or a genuine error, there may be grounds to challenge a penalty, but this depends on the facts and should not be assumed.
The better outcome is to make deadlines part of a dependable finance rhythm. Stewart Accounting Services helps businesses turn scattered records and looming dates into timely accounts, tax returns and practical financial visibility. With the right support and current information, compliance stops taking attention away from the business you are working hard to build.