Overview
Self Assessment is a system HM Revenue and Customs (HMRC) uses to collect Income Tax.
Tax is usually deducted automatically from wages, pensions and savings. People and businesses with other income must report it in a tax return.
If you need to send one, you fill it in after the end of the tax year (5 April) it applies to.
Who must send a tax return
You must send a tax return if, in the last tax year (6 April to 5 April), you were:
- self-employed as a ‘sole trader’ and earned more than £1,000
- a partner in a business partnership
You will not usually need to send a return if your only income is from your wages or pension. But you may need to send one if you have any other untaxed income, such as:
- money from renting out a property
- tips and commission
- income from savings, investments and dividends
- foreign income
Check if you need to send a tax return if you’re not sure.
Registering and sending a return
You need to register if you did not send a return last year. There are different ways to register if you’re:
If you’re new to Self Assessment, you’ll need to keep records (for example bank statements or receipts) so you can fill in your tax return correctly.
Other reasons for sending a return
You can choose to fill in a tax return to:
- claim some Income Tax reliefs
- prove you’re self-employed, for example to claim Tax-Free Childcare or Maternity Allowance
If you get Child Benefit
If your income (or your partner’s, if you have one) was over £50,000, you may need to send a return and pay the High Income Child Benefit Charge.
Deadlines
HM Revenue and Customs (HMRC) must receive your tax return and any money you owe by the deadline.
The tax year starts on 6 April and ends on 5 April.
| Self Assessment | Deadline |
|---|---|
| Register for Self Assessment if you’re self-employed or a sole trader, not self-employed, or registering a partner or partnership | 5 October (during the tax year) |
| Paper tax returns | Midnight 31 October |
| Online tax returns | Midnight 31 January |
| Pay the tax you owe | Midnight 31 January |
There’s usually a second payment deadline of 31 July if you make advance payments towards your bill (known as ‘payments on account’).
You’ll usually pay a penalty if you’re late. You can appeal against a penalty if you have a reasonable excuse.
Penalties
You’ll get a penalty if you need to send a tax return and you miss the deadline for submitting it or paying your bill.
You’ll get a penalty of £100 if your tax return is up to 3 months late. You’ll have to pay more if it’s later, or if you pay your tax bill late. You’ll also be charged interest on late payments.
Estimate your penalty for Self Assessment tax returns more than 3 months late, and late payments.
You can appeal against a penalty if you have a reasonable excuse.
All partners can be charged a penalty if a partnership tax return is late.