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
Completing your tax return (individuals and directors)
If you have straightforward tax affairs and already pay tax from a job or pension income through Pay As You Earn (PAYE) you probably won't need to fill in a tax return. But if you're a higher rate tax payer, a company director or have more complicated tax affairs you may need to complete one.
On this page:
- Filling in the short return
- Filling in your tax return online
- Key steps for filling in your full tax return
- Step one - check you've got the right pages
- Step two - complete the supplementary pages
- Step three - complete the core pages and additional information pages
- What happens if you don't have exact figures?
- Deadline for sending in your return
- Avoiding common mistakes
- If you have problems completing your tax return
Filling in the short return
If your tax affairs are straightforward you might qualify for the short tax return rather than the longer full one. If you do, we'll send it to you. The short tax return is only four pages long and the accompanying notes will help you fill it out. It cannot be submitted online. If you prefer to submit your tax return online you have to complete the full return instead.
The records you'll need to complete the short return are similar to the ones you'll need for the core pages of the full return. To find out more go to 'Step three - complete the core pages'.
Except in very rare circumstances company directors can not fill out the Short Return.
The short tax return - get further information
Filling in your tax return online
You can fill in the full tax return on paper or complete it online.
If you submit the return online the software automatically calculates any tax payable and instantly acknowledges that HM Revenue & Customs (HMRC) have received your return. You'll also have 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 31 October.
You'll need to register for Online Services on the HMRC website if you want to submit your return online.
Self Assessment Online - find out more about the benefits and how to register
Key steps for filling in your full tax return
The paper version of the main tax return has two core forms (SA100 and SA101) as well as supplementary pages (for example for employment income or income from property) tailored to your needs. If you get the full tax return you'll need to:
- check you've got the right pages - if it's a paper return
- get together the paperwork and records you'll need
- fill in the core pages and additional information pages that apply to you
- fill in any supplementary pages that apply to you
- send the completed return to your Tax Office within the deadline
Tax return and payment deadlines - read the current dates
Step one - check you've got the right pages
If you file online
If you file online, simply select the supplementary pages you need. The HMRC software provides most (but not all) of the supplementary pages online. You may, however, be able to submit these pages using third-party software.
If you complete a paper return
If you complete a paper return it will tell you if you need to fill in any supplementary pages. You can download any missing pages and help notes from our website.
Go to Self Assessment forms, guidance and supplementary pages
Step two - complete the supplementary pages
For the relevant tax year (6 April to the following 5 April) you'll need records relating to:
- your employment
- pension contributions you make or any pension you receive
- income you might get from letting a property or land
- any capital gains or losses you've made during the tax year
Record keeping for individuals and directors - learn more
Record keeping - read a general guide
Step three - complete the core pages and additional information pages
Paperwork you'll need
For the relevant tax year you'll need records of:
- UK savings and investments
- UK pensions, annuities and benefits
- life insurance gains and AVC refunds
- any other taxable income
Record keeping for individuals and directors - learn more
Reliefs, allowances and student loan repayments
If you want to claim relief for retirement annuity and pension contributions and for costs such as gifts to charity, you'll need records showing that you've made these payments.
If you're paying back a student loan and your income is over £15,000, you can make payments through either Self Assessment or PAYE along with any tax and National Insurance contributions (NICs).
Contact and bank details
We'll ask you for:
- a phone number so that your Tax Office can deal with straightforward queries quickly
- bank details if you want any tax repaid directly to your account (this is recommended)
What happens if you don't have exact figures?
If you don't have exact figures you can use:
- an estimate - a figure you want us to accept as your final figure
- a provisional figure - one you want to use until you can confirm the actual amount (you must tell us when you will be supplying actual figures)
Use the 'Additional Information' section to say how you arrived at these figures and why you can't use actual figures. If you make adjustments later and you've underpaid tax you may have to pay interest and penalties.
Deadline for sending in your return
The deadlines for sending us your return are:
- you must send paper tax returns to us by 31 October (or 3 months after the date of issue of the notice - whichever is the later)
- if you send in an online tax return you've got until 31 January (or 3 months after the date of issue of the notice - whichever is the later)
Tax return deadlines and penalties
Receipts are not provided for paper tax returns. If you file online you'll get an immediate, on-screen acknowledgment that we've received your return.
Avoiding common mistakes
So that we can process your return quickly:
- make sure you sign and date it if it is a paper return
- check that you've completed and included any supplementary pages needed
- don't include notes on the return like 'information to follow'
- don’t alter the year on a return to use it as a substitute for another year (unless you're changing it to this tax year as the relevant form isn't yet available)
Filing online can help you to avoid making mistakes. Follow the link below to find out how to register to file your tax return online.
Self Assessment Online - find out more about the benefits and how to register
If you have problems completing your tax return
If you need help you can ring the Self Assessment Helpline on Tel 0845 900 0444. It's open from 8.00 am to 8.00 pm every day, except Christmas Day, Boxing Day and New Year's Day.
