When Is Self Assessment Tax Return Due?
Discover the critical timelines and essential processes for managing your UK Self Assessment tax return, from preparation to final payment.
Self Assessment is the system HM Revenue & Customs (HMRC) uses to collect Income Tax from individuals who earn income not typically taxed at source, such as through a traditional employment payroll system. This includes self-employed individuals, those receiving rental income, or anyone with significant untaxed income or capital gains. By requiring these individuals to report their earnings and expenses, HMRC can accurately calculate their tax liability.
Annual Filing and Payment Deadlines
The tax year runs from April 6th to April 5th of the following year. For instance, the tax year ending on April 5th, 2025, requires reporting for that period.
The deadline for submitting a paper Self Assessment tax return is October 31st following the end of the tax year. Most individuals file their tax returns online, which offers a later deadline. The online submission deadline is January 31st of the year following the tax year end. For the tax year ending April 5th, 2025, the online filing deadline is January 31st, 2026.
The payment deadline for any tax due for the previous tax year is also January 31st. This payment, known as a “balancing payment,” settles any remaining tax owed for that year. Many taxpayers are also required to make advance payments towards their next tax bill, known as “payments on account.” These payments are due in two equal installments: the first by January 31st and the second by July 31st. Each payment represents 50% of the previous year’s tax bill.
Gathering Your Information for Filing
Preparing your Self Assessment tax return requires financial documents. This helps ensure accuracy and streamline the filing process. You will need details for all sources of income received during the tax year.
For employed income, P60 forms summarize annual earnings and deductions. If you left a job, a P45 form provides details. Self-employment income requires records, including invoices, receipts, and bank statements for business transactions. Income from other sources, such as rental properties, bank interest, dividends, or foreign earnings, requires statements or vouchers.
Beyond income, you must gather records of allowable expenses. These can include business costs, professional subscriptions, and pension contributions. Keeping detailed records of these expenses is important for calculating taxable income and claiming eligible reliefs. Other financial information, like capital gains details or student loan repayment statements, should be available.
Submitting Your Self Assessment Tax Return
Once your financial information is compiled and your tax return prepared, you can proceed with submission. The most common method for filing is online, through HMRC’s Self Assessment portal. This requires a Government Gateway ID, a 12-digit unique identifier that allows secure access to HMRC online services.
To submit online, log into your Government Gateway account on the HMRC website, navigate to the Self Assessment section, and input your Unique Taxpayer Reference (UTR) number. The online system guides you through sections to input income and expense details. You can save your progress and return later. After all sections are completed and reviewed, submit the return electronically, and you receive immediate confirmation.
For paper returns, obtain the correct forms, primarily the SA100 and any supplementary pages relevant to your income sources. These forms must be completed by hand or printed and mailed to the designated HMRC address. Sending it online is generally recommended for faster processing and confirmation.
Making Your Tax Payment
After submitting your Self Assessment tax return and calculating the tax owed, make the payment to HMRC by the deadline. Several payment methods are available.
You can pay your tax bill directly through your online bank account using Faster Payments, CHAPS, or Bacs, which process within the same or next working day. Another option is paying by debit card or corporate credit card online via the HMRC website. Direct Debit is also an option; setting up a new Direct Debit may require a few working days to clear. Payments can also be made by cheque through the post. This method takes longer to process.
When making any payment, use the correct 11-character payment reference number. This reference is your 10-digit Unique Taxpayer Reference (UTR) followed by the letter ‘K’. Using the accurate reference ensures your payment is correctly allocated to your tax account.