Self Assessment: the essentials

What is a Self Assessment tax return?

Self Assessment and a tax return are the same thing. You might hear it called Self Assessment, a tax return, or a Self Assessment tax return.

What does ‘filing’ a tax return mean?

‘Filing’ your tax return simply means completing your tax return and sending it to HMRC.

Who needs to file a Self Assessment tax return?

For most people, tax is paid automatically through their employer or pension provider (known as PAYE). You’ll need to complete a Self Assessment tax return if you have sources of income that aren’t automatically taxed when you get them. This could include income from:

• Self-employment
• Buying and selling
• Providing services
• Renting property
• Savings and investments
• Capital gains
• Foreign income

Learn more about who needs to complete a tax return

Important deadlines to remember.

These are the key dates to remember for your Self Assessment tax return:

• 5 October: Deadline to register for Self Assessment (if you’re new and haven’t registered before)
• 31 October: Deadline for paper returns
• 31 January: Deadline for online returns and tax payments

Find out more about deadlines and penalties.

What will I need to file my tax return?

To complete your return accurately, you’ll need several key documents and details. These include:

• Unique Taxpayer’s Reference Number
• Income details (employment, self-employment, rental, dividends)
• Records of allowable expenses and tax reliefs
• P60, P45, pension statements, and bank interest information
• It’s good to keep these documents somewhere safe throughout the year. It will make completing your tax return easier.

Find out more about what records you need to file your tax return depending on your income: