The following Self-Assessment guidance produced by Spondoo Accountants has comprehensive information covering:
- What is a Self-Assessment Tax Return?
- Who needs to complete a Self-Assessment tax return?
- How to register for Self-Assessment
- Self-Assessment important dates and deadlines
- Fines and penalties for late filing and payment of Self-Assessment tax bill
- Records to keep
- How to submit a Self-Assessment tax return.
- What to do if you no longer have to submit a Self-Assessment tax return
- What is a Simple Assessment?
- What is a Short tax return?
- Self-Assessment guides and support
What is a Self-Assessment Tax Return?
If you receive income or capital gains that do not have tax automatically deducted via your employer’s payroll/PAYE system – you will need to report this under a self-assessment.
The Self-Assessment personal tax return informs HMRC about your taxable income and gains for a tax year and is submitted online or by paper annually.
You are solely responsible for informing HMRC that you need to file this tax return, and you must not wait for them to contact you first. When you send in your personal tax return, HMRC or your accountant will calculate your tax liability – and you may have (or not) to pay any tax due for that year.
Do I need to complete a Self-Assessment tax return?
You may be liable for a Self-Assessment tax return if you receive any untaxed income above certain thresholds. Therefore, Self-Assessment does not apply to everyone receiving untaxed/gross income or gains.
To be clear, you must submit a tax return if any one of the following applies to you:
- Self-employed and your income is not within the annual £1,000 trading allowance.
- A company director with an income that has not been taxed under PAYE – unless you are the director of a not-for-profit organisation
- A partner in a business partnership
- A landlord or you receive property income (unless this income qualifies for rent-a-room relief or is within the annual £1,000 property allowance)
- A trustee or the executor of an estate
- You intend to claim tax relief on employment expenses over £2,500 in a year.
- If you earned £10,000 or more from savings interest or investment income
- An employee or pensioner who earned £100,000 or more last tax year.
- You earned £2,500 or more in untaxed income – for example, from tips or commission.
- A UK non-resident with a taxable income in the UK
- A UK non-resident landlord getting rental income in the UK.
- You have an annual income of £100,000 or more before tax.
- If you have income from savings and investments of £10,000 or more before tax
- You have tax due at the end of the year that cannot be collected via your PAYE coding notice in a later year.
- If you get state pension payments that exceed your personal allowance and it’s your only source of income.
- If you pay the High Income Child Benefit charge because you claim child benefit – yet your adjusted net income or your partner’s income is over £50,000.
- You get a P800 form from HMRC saying you didn’t pay enough tax last year – and you haven’t yet paid the outstanding sum.
- If you are required to pay Capital Gains Tax on profits from selling things like shares or a second home
- A religious minister from any denomination
- Received (claimed) coronavirus support payments erroneously – and have not repaid HMRC.
If you are still unsure if you have to complete a Self-Assessment tax return, you can use the HMRC Self-Assessment tool to confirm.
How to register for Self-Assessment
You must register for Self-Assessment by 5 October. There are different ways of registering for Self-Assessment depending on whether you are a partnership, sole trader, or not self-employed. We have discussed what to do in each case.
How to register for Self-Assessment if you are self-employed (sole trader)
As a self-employed person, how you register for Self-Assessment depends on how you want to submit your tax return – online or on paper.
Online registration
To register online, follow the following process:
- Sign up (if you have not) for the Government Gateway – to get a user ID and password.
- Register for Self-Assessment and Class 2 National Insurance through your Government Getaway portal – through your business tax account.
- HMRC will send you a letter containing your Unique Taxpayer Reference (UTR) number – it is used to file your return. It will arrive after ten days if you are in the UK and may take up to 21 days if you are abroad.
- HMRC will send you a letter or e-mail reminding you to complete your Self-Assessment tax return before it’s due.
If you have submitted an online tax return before, use the following process to re-register for Self-Assessment:
- Find your 10-digit Unique Taxpayer Reference (UTR) from when you registered before.
- Sign in to your Government Getaway account.
- Re-register online (form CWF1) for Self-Assessment and Class 2 National Insurance.
- HMRC will send you a reminder letter or e-mail telling you to complete a Self-Assessment tax return before it’s due.
If you have filed a tax return before but did not use the online service, follow the following process:
- Sign in to your Government Getaway account.
- Sign in to your business tax account.
- Add Self-Assessment to your account – as described in the first instance (when you have not submitted a tax return online before).
Register by post
Follow the following steps:
- Fill out this form online. You must fill in all the information necessary for you.
- Print out the filled form.
- Send the form to HMRC via:
If you live in the United Kingdom send it to:
Self Assessment
HM Revenue & Customs
BX9 1AS
United Kingdom
If you live outside the UK send to:
HM Revenue & Customs
Benton Park View
Newcastle Upon Tyne
NE98 1ZZ
United Kingdom
- HMRC will send you a letter with your Unique Taxpayer Reference (UTR) number within ten working days. It may take up to 21days if you are abroad.
- HMRC will send you a reminder letter reminding you to complete a Self-Assessment tax return before your return is due.
How to register for Self-Assessment if you are not self-employed
If you are not self-employed but want to fill out a Self-Assessment tax return – do the following:
Online
To register online, follow the following process:
- Sign up (if you have not) for the Government Gateway – to get a user ID and password.
- Register for Self-Assessment and Class 2 National Insurance through your Government Getaway portal – through your business tax account.
- HMRC will send you a letter containing your Unique Taxpayer Reference (UTR) number – it is used to file your return. It will arrive after ten days if you are in the UK and may take up to 21 days if you are abroad.
- HMRC will send you a letter or e-mail reminding you to complete your Self-Assessment tax return before it’s due.
By post
To register by post, follow the following steps:
- Fill out this form online. You must only fill in all the information necessary for you.
- Print out the filled form.
- Send the form to HMRC via:
If you live in the UK, send to:
Self Assessment
HM Revenue & Customs
BX9 1AS
United Kingdom
If you live outside the UK send to:
HM Revenue & Customs
Benton Park View
Newcastle Upon Tyne
NE98 1ZZ
United Kingdom
- HMRC will send you a letter with your Unique Taxpayer Reference (UTR) number within ten working days. It may take up to 21days if you are abroad.
- HMRC will send you a reminder letter telling you to complete a Self-Assessment tax return before your return is due.
How to register for Self-Assessment if you’re a partner or partnership
If you are a partner in a partnership, you must register for Self-Assessment by 5 October. You may register:
Online
Register your LLP online following the following process:
- Sign up (if you have not) for the Government Gateway – to get a user ID and password.
- Register for Self-Assessment and Class 2 National Insurance through your Government Getaway portal – through your business tax account.
- HMRC will send you a letter containing your Unique Taxpayer Reference (UTR) number – it is used to file your return. It will arrive after ten days if you are in the UK and may take up to 21 days if you are abroad.
- HMRC will send you a letter or e-mail reminding you to complete your Self-Assessment tax return before it’s due.
By post
Follow the following steps:
- Fill out this form online. You must fill in all the information necessary for you.
- Print out the filled form.
- Send the form to HMRC via:
If you live in the UK, send to:
Self Assessment
HM Revenue & Customs
BX9 1AS
United Kingdom
If you live outside the UK, send to:
HM Revenue & Customs
Benton Park View
Newcastle Upon Tyne
NE98 1ZZ
United Kingdom
- HMRC will send you a letter with your Unique Taxpayer Reference (UTR) number within ten working days. It may take up to 21days if you are abroad.
- HMRC will send you a reminder letter reminding you to complete a Self-Assessment tax return before your return is due.
Print PDF and fill it by hand
Follow the following steps:
- Download this form from the HMRC website.
- Fill in all the information necessary to you by hand.
- Send the form to HMRC via:
If you live in the UK, send to:
Self Assessment
HM Revenue & Customs
BX9 1AS
United Kingdom
If you live outside the UK, send to:
HM Revenue & Customs
Benton Park View
Newcastle Upon Tyne
NE98 1ZZ
United Kingdom
- HMRC will send you a letter with your Unique Taxpayer Reference (UTR) number within ten working days. It may take up to 21days if you are abroad.
- HMRC will send you a reminder letter asking you to complete a Self-Assessment tax return before your return is due.
Self-Assessment important dates and deadlines
It is crucial to understand the Self-Assessment tax dates and deadlines in a given tax year to avoid incurring potential late filing and payment penalties.
Some of the deadlines you must bear in mind are:
| Self-Assessment date | Deadline |
| 5th October | Self-Assessment registration Tell HMRC you must submit a tax return the following year. |
| 31st October | Submit paper tax returns Your paper tax return must arrive at HMRC before midnight on October 31st. |
| 30th December | Opt into PAYE You can choose to have overdue tax collected via PAYE if you file your tax returns online and have earnings taxed under PAYE. However, this can only apply if your tax bill is below £3,000, and you agree to file your online return by this date. |
| 31st January | Submit online tax returns Submit your Self-Assessment tax return online by midnight on January 31. |
| 31st July | First Payment on account The deadline for your first payment on account – If you pay your tax through the payment on account. |
Fines for being late with Self-Assessment tax return deadlines
You may attract a penalty or interest charges if you file your tax return late – or fail to pay the tax you owe on time. Some of the potential fines include:
| How late | Charge |
| One day late | £100 for one day after the deadline |
| Three months late | £10 for each additional day (capped at 90 days), plus a £100 initial fine – a maximum of £1,000 |
| Six months late | Either £300 or 5% of the tax due (whichever is higher), on top of the penalties above |
| Twelve months late | An additional £300 fine, or 5% of the tax due, plus the above penalties. In the most serious cases, you could be fined 100% of the tax due. |
You can estimate your potential charges here if you are three months late in submitting your return – or making payments.
Records to keep
It is crucial to keep records because you may be forced to pay a penalty if you fail to produce them when asked by HMRC. You will also need the correct details when you file your return.
The length of time you can hold on to the records depends on if you are:
- An Individual: Keep your records for 22 months from the end of the tax year to which they relate – if you filed your return on time. However, you must keep your records for an extended period if – you file your tax return late, you are buying or selling assets, or HMRC are looking into your return.
- Self-employed or in a partnership: if you file your tax return on time, you may keep your records for at least five years from 31 January following the tax year of the return. Contrarily, you must keep your records for an extended time if – you file your tax return late, you are buying or selling assets, or HMRC are looking into your return.
The types of records should reflect the claims you make to HMRC. They could be personal financial records or documents you have signed or have been given.
Submitting a Self-Assessment tax return – what you will need
Even though you can submit a Self-Assessment tax return yourself, hiring a personal tax accountant to do it for you will ensure your return is submitted accurately – and may minimise your tax liability.
Before you start submitting your tax return, it is important to have some documents on hand to ease the process. They may include:
- Benefits claimed (including child benefit)
- Unique Taxpayer Reference (UTR)
- National Insurance number
- P60 or P45 forms if you were employed for that tax year.
- P11D where applicable.
- Income records like employment earnings, rent
- Gifts or donations made to a charity
- Details of any compensation received
- Details of tax avoidance schemes that you are part of.
- Work-related expenses if you are self-employed
- Investments you hold (or have sold in the tax year)
- Interest earned
- Pension / State Pension income
- Student loan repayments
- Redundancy payments
You can complete your tax return online or by post.
How to Submit your Self-Assessment tax return – step by step process
Find an accountant to file your personal tax return.
You can either submit online or by post.
How to submit online
To submit your tax return online:
- Sign in to your Government Getaway account using your User ID and password.
- Welcome page
- Tell us about you: in this section, fill in the details on the screen as prompted.
- If a box lights up red, you may have filled the information incorrectly – correct it.
- If you get stuck and are unsure what to answer, click on the links on the screen to guide you.
- Tailor your return: in this section, only answer questions that apply to you.
- You may click on the Help About link for guidance – if you are unsure about something.
- Check your return: you can see how much you owe HMRC in this section.
- Save your return: you can click on save and continue to go to the next section.
- You can go through your return once completed and Go Back if you need to change anything.
- Submit your return – you will need your user Id and password to send your return to HMRC.
- When you are done, HMRC will send you an online message to confirm you have successfully submitted your tax return.
How to submit by post
To submit your return by paper:
- Use this form from the HMRC website.
- Fill in the details online – according to your circumstances. Here is a guide on filling out the form.
- Download the completed form.
- Post your completed paper tax return to HMRC.
Note: You can also download the PDF form and complete it by hand.
If you live in the UK, send to:
Self Assessment
HM Revenue & Customs
BX9 1AS
United Kingdom
If you live outside the UK, send to:
HM Revenue & Customs
Benton Park View
Newcastle Upon Tyne
NE98 1ZZ
United Kingdom
I’m no longer eligible for Self-Assessment – how do I deregister?
It is important to inform HMRC (as soon as possible) when your circumstances change, and you don’t need to complete a Self-Assessment tax return.
Please read our article on how to deregister from Self-Assessment here.
HMRC may refuse to cancel your Self-assessment registration. In that case, they may ask you to complete your tax return and explain your change in circumstances in the Additional Information section.
If HMRC feels you have not paid enough tax, they may agree to cancel your Self-Assessment tax return but issue you with a Simple Assessment.
What is a Simple Assessment?
Simple Assessment allows the government to assess the capital gains and income tax liability of some taxpayers using the information provided by third parties like – The departments of Work and Pensions (employers and pension providers), banks and other organisations.
If you qualify for Simple Assessment, you do not have to complete the normal Self-Assessment return. HMRC will write to you with a tax calculation via a Simple Assessment letter (PA302). The return will also contain the date payment is due and how the payment can be made.
It is important to check the figures presented by HMRC in the Simple Assessment Tax payment request. You only have 60 days to appeal if you find any discrepancies in the tax return.
If the value calculated and issued to you is correct, you can pay the amount using:
- Online or telephone banking – takes up to 3 working days for your payment to reach HMRC. If you are in the UK use:
| Sort code | Account number | Account name |
| 08 32 10 | 12001020 | HMRC Shipley |
If you are using an overseas bank account, use:
| Bank Identifier Code (BIC) | Account number (IBAN) | Account name |
| BARCGB22 | GB03BARC20114783977692 | HMRC Shipley |
- Debit or corporate credit card – HMRC will accept your card payment on the date you make it.
To do this:
Start your Simple Self-Assessment payment.
Choose whether to sign in to your account or not.
Enter your payment details and amount.
Click Continue
Follow the subsequent prompts.
- By cheque – takes 3 working days for your payment to reach HMRC.
You should put your Self-Assessment Tax reference number on the back of the check. Make the cheque payable to ‘HM Revenue and Customs only’ and send it to:
HMRC
Direct
BX5 5BD
The deadline for payment is either:
- 31st January following the end of the tax year.
- Three months after the date of the Self-Assessment letter – if you completed your return later than 31st January.
To avoid incurring late payment penalties, you should call HMRC and explain your circumstances – if you cannot pay your tax bill on time.
What is a short tax return (SA200)?
The short tax return (SA200) is a simplified Self-Assessment return issued by HMRC to a section of taxpayers who have simple tax affairs – to reduce their compliance burden. Some of the taxpayers who may be issued this return include:
- Employees (who are not directors) with taxable benefits. If you receive it and you are a director, you must check the SA200 filling guide to see if you are eligible.
- Sole traders (self-employed) with a taxable turnover that is lower than the annual VAT registration threshold.
- Pensioners who have pensions and straightforward investment income.
You cannot self-select a short tax return – and HMRC only writes to you based on your previous tax return entries.
The return only covers the most common:
- Sources of income – pensions, employment, self-employment, UK property, and investment income.
- Reliefs – personal allowances, gift aid and pension contributions.
The return also asks a few questions. Consequently, if you have capital gains and losses – you must report them on the usual capital gains summary supplementary pages and submit it with the short tax return.
You cannot calculate the tax due on the return, but HMRC provides a simple guide which you may use to make an estimate calculation of the tax due.
If you get a short tax return request from HMRC – do not rule out the possibility of submitting the main tax return – based on your individual circumstances. It is also crucial to read the Short Tax Return guide to see if it applies to you and how to fill the return.
The Short Tax Return is filed by:
- Post – 31 October following the end of the tax year.
- Online – 31 January following the end of the tax year.
Other important things to know about the return:
- It is not available online or in local offices.
- You cannot use it unless it is issued to you by HMRC. Neither can you use a Short Tax Return issued to another person – for your personal tax.
- You can opt out of using it – and send in the main Self-Assessment return in place of the Short Tax Return.
- Do not send the return with any additional attachments. Only attach the acceptable capital gains supplement and computations where applicable.
Get Self-Assessment Guides and support
Self-Assessment is a delicate subject that should be handled with care. If you are unsure of your expenses and claimable allowances, you may end up paying more tax than you should. Additionally, you may attract penalties if you make mistakes in your return. Luckily, we have a team of Self-Assessment experts who can help you – depending on your needs. Feel free to contact our personal tax team for help and support with all your self-assessment needs.
There is also plenty of information on Self-Assessment on the HMRC website.
