Self Assessment Tax Return
Self Assessment is the UK system used by HMRC for individuals who must report their income and calculate their own tax each year.
Instead of tax being fully deducted automatically (like PAYE employees), you declare your income and expenses through an annual tax return.
Who needs to file a Self Assessment return?
You usually need to file if you:
- Are self-employed (sole trader or freelancer)
- Are a landlord with rental income
- Have foreign income
- Have capital gains to report
- Are a company director (in many cases)
- Receive other untaxed income (consulting, side projects, etc.)
Amanda may flag a Self Assessment obligation if your profile shows UK tax residency or UK-source income.
What does the return cover?
A Self Assessment tax return typically includes:
- Employment income (if relevant)
- Self-employment profits
- Rental income (UK and sometimes overseas)
- Interest and dividends
- Capital gains
- Foreign income
HMRC uses this information to calculate how much tax you owe (or if you are due a refund).
Key deadlines
The UK Self Assessment tax year runs from 6 April to 5 April.
Typical deadlines:
| Date | What |
|---|---|
| 5 October | Register for Self Assessment (if newly required) |
| 31 October | Paper return deadline |
| 31 January | Online return deadline + payment of tax owed |
| 31 July | Second "payment on account" (if applicable) |
Missing deadlines can lead to automatic penalties and interest.
How you file
Self Assessment is filed through HMRC Online Services using your Government Gateway account.
You will need:
- Your UTR (Unique Taxpayer Reference)
- Access to your HMRC online account
- Records of income and expenses for the tax year
Most people file online. Paper returns are now rare and have earlier deadlines.
Payments on account
If your tax bill is high enough, HMRC may require payments on account:
- Two advance payments toward the next tax year
- Due 31 January and 31 July
This often surprises new landlords and freelancers, as you effectively start paying next year's tax in advance.
What Amanda helps you understand
Amanda does not file your return directly, but it helps you:
- Identify whether Self Assessment likely applies to you
- Understand why you are in scope (e.g. rental income, UK ties, residency)
- Track the type of income that typically feeds into a UK return
- Prepare for deadlines and documentation you'll need
If Amanda shows UK tax exposure, Self Assessment is usually the mechanism through which you stay compliant.
Official source
For official guidance, registration, and filing, refer to HMRC's Self Assessment pages on GOV.UK.