In this section:
- Introduction to Self Assessment
- Do you need to complete a tax return?
- Completing your tax return (individuals and directors)
- Record keeping (individuals and directors)
- Tax return deadlines and penalties
- Understanding and using Self Assessment Online
- Understanding your tax calculation
- Understanding your Self Assessment Statement
- How to pay your tax
- What to do if you can't pay your tax bill
Introduction to Self Assessment
Self Assessment involves completing an online or paper tax return in order to tell us about your income and capital gains (profits on the sale of certain assets), or to claim tax allowances or reliefs against your tax bill. We use the figures on the tax return to work out your tax bill, or you can work it out yourself.
There are different types of tax return and different 'supplementary pages' you may need to complete depending on your circumstances. There are also deadlines for sending your tax return in - and penalties and interest charges if it arrives late.
You can file most tax returns online - the section 'Benefits of filing online' explains the advantages of this method.
On this page:
- Who needs to complete a Self Assessment tax return?
- Asking to complete a Self Assessment tax return
- Benefits of filing online
- Software you can use to file your tax return
- Find out more about Self Assessment
Who needs to complete a Self Assessment tax return?
If you pay tax on your earnings or pensions through PAYE (Pay As You Earn) your employer or pension provider deducts tax on our behalf and you won't usually need to complete a tax return. In these cases we'll normally also ask them to use the PAYE system to deduct any tax you may owe on a State Pension or other taxable income (eg investment or rental income) up to a certain level.
But if you have more complicated tax affairs you may need to complete a tax return. There are also certain circumstances in which you will always need to complete a tax return - for example if you're self-employed, a company director or a trustee or if you have foreign income.
Follow the link below to read the full detail on who needs to complete a tax return and to find out more about the different types of tax return.
Find out more about who needs to complete a tax return
Asking to complete a Self Assessment tax return
Self Assessment tax returns are normally sent out in April each year (or a notice to fill in a tax return if you file online). If you've not received a return but think you should complete one contact your Tax Office. Your employer or pension provider will have details of this, or you can search online.
You can ask to complete a tax return at any time - for example, if you want to claim a particular tax relief or exemption. We'll send you a return if necessary. (You can't send us a Self Assessment return without first contacting us.)
If you are newly self-employed, our guide 'Tax returns if you're self-employed or in a partnership' tells you how to register as self-employed - you'll then be sent a Self Assessment tax return if necessary.
Tax returns if you're self-employed or in a partnership
Benefits of filing online
Filing online has many advantages - for example the software will automatically calculate any tax payable. You'll also have three months longer to file the return than if you use a paper form - you'll have until 31 January following the end of the tax year instead of the previous 31 October.
To register for Self Assessment Online you'll need your ten-digit Unique Taxpayer Reference (UTR). You'll find your UTR on correspondence from HMRC or you can contact your Tax Office and ask for your UTR - it can only be sent in the post to your home address.
If you are new to Self Assessment, your UTR will be on your welcome letter (SA250).
File your tax return online - more about the benefits and how to register
Software you can use to file your tax return online
You can use our free Self Assessment Online software or commercial software (some are also free) to file your tax return online.
Some types of tax return (for example the Trust and Estate Tax Return and the Partnership Return) and some supplementary pages (for example, those for Lloyd's members and ministers of religion) aren't supported by our service, but are provided by commercial software.
Find out what software you can use to file your tax return online
Currently no software is available for filing the following returns:
- SA700 - Non-resident Company Tax Return
- SA970 - Trustees of Registered Pension Schemes
You have to send these as paper returns. Because there is no online service available, the deadline for these paper returns is the same as for online returns - 31 January.
Find out more about Self Assessment
Follow the links on the left to find out more about completing a return if you are an individual or a director. You'll also find out about key dates and deadlines, the benefits of filing online, Self Assessment record keeping and more.
To go directly to information about tax returns for specific groups follow the links below.
Tax returns if you're self-employed or in a partnership
Dealing with a tax return for someone who has died
Tax returns for trustees or charities
