Self Assessment tax returns in the UK: deadlines & basics

Who must send a return

You may need to send a Self Assessment tax return if, for example, you are self-employed, a partner in a business, a company director, or have untaxed income. HMRC’s questionnaire and guidance explain who must register.

Check if you need to send a Self Assessment tax return

Key deadlines (typical)

For online returns, the usual filing deadline for a given tax year is 31 January following the end of that tax year. The same date often applies for paying the balancing payment for that year. There are separate deadlines for paper returns if you use them.

Always use the Self Assessment deadlines page for the tax year you are in—HMRC can charge penalties for late filing and late payment.

Payments on account

If you pay tax in advance by instalments, HMRC may require payments on account towards your next bill. Amounts and due dates are explained on GOV.UK.

Payments on account

MTD for Income Tax

HMRC is introducing Making Tax Digital for Income Tax in stages. If you are in scope, digital record-keeping and quarterly updates apply—see our MTD for Income Tax guide and GOV.UK.

Official sources

• Self Assessment tax returns
• Log in to file your Self Assessment

Related guides

• Starting a business in the UK
• MTD for Income Tax