Self Assessment is a system HM Revenue and Customs ( HMRC ) uses to collect Income Tax. Tax is usually deducted automatically from wages and pensions. People and businesses with other income must report it in a Self Assessment tax return. If you need to send a Self Assessment tax return , fill it in after the end of the tax year (5 April) it applies to. You must send a return if HMRC asks you to. You may have to pay interest and a penalty if you do not file and pay on time. This guide is also available in Welsh (Cymraeg) . Sending your return You can file your Self Assessment tax return online . If you need a paper form you can: download the SA100 tax return form call HMRC and ask for the SA100 tax return form Deadlines Send your tax return by the deadline . You must tell HMRC by 5 October if you need to complete a tax return and you have not sent one before. You could be fined if you do not. You can tell HMRC by registering for Self Assessment. Check how to register for Self Assessment . Filling in your return You need to keep records (for example bank statements or receipts) so you can fill in your tax return correctly. You can get help filling in your return . Paying your bill HMRC will calculate what you owe based on what you report. Pay your Self Assessment bill by 31 January. How much tax you pay will depend on the Income Tax band you’re in. There’s a different rate for Capital Gains Tax if you need to pay it, for example you sell shares or a second home.

Who must send a tax return

You must send a tax return if, in the last tax year (6 April to 5 April), any of the following applied: you were self-employed as a ‘sole trader’ and earned more than £1,000 (before taking off anything you can claim tax relief on) you were a partner in a business partnership you had to pay Capital Gains Tax when you sold or ‘disposed of’ something that increased in value you had to pay the High Income Child Benefit Charge You may also need to send a tax return if you have any untaxed income, such as: money from renting out a property tips and commission income from savings, investments and dividends foreign income Check if you need to send a tax return You can check if you need to send a tax return if you’re not sure. You must tell HMRC by 5 October if you need to complete a tax return and have not sent one before. You can tell HMRC by registering for Self Assessment. Other reasons for sending a return You can choose to fill in a tax return to: claim some Income Tax reliefs prove you’re self-employed, for example to claim Tax-Free Childcare or Maternity Allowance pay voluntary National Insurance contributions

You can send a tax return by either: submitting an online return sending a paper return You can get help filling in your return . When to send your tax return Check the filing deadlines . The deadline for sending a paper return is before the deadline for an online return. You can send your return any time after 5 April. Sending it earlier means you: find out what you owe can budget - if you want to make weekly or monthly payments have time to pay your bill by 31 January can set up a payment plan , if you do not think you can pay on time Submit an online return You can file your Self Assessment tax return online . Send a paper return If you need a paper copy of the main Self Assessment tax return you can: download the SA100 tax return form call HMRC and ask for the SA100 tax return form If you need to send a tax return for trustees of a registered pension, you must download form SA970 . You can download all other forms and supplementary pages . After sending your paper return, you can check when to expect a reply from HMRC . Use commercial software to send a return You can use commercial software: for a partnership for a trust and estate if you get income from a trust if you lived abroad as a non-resident if you’re a Lloyd’s underwriter if you’re a religious minister to report profits made on selling or disposing of more than one asset (‘chargeable gains’) Find a commercial software supplier .

If you no longer need to send a tax return

You must tell HMRC as soon as possible if you believe you no longer need to send a tax return. HMRC needs time to review your request before the Self Assessment deadline of 31 January. You may have to pay a penalty if you do not tell them early enough. When you no longer need to send a tax return You might no longer need to send a return because, for example: you’ve stopped being self-employed you no longer rent out property you no longer pay the High Income Child Benefit Charge You can check if you need to send a tax return if you’re not sure. How to tell HMRC Sign in to your account and fill in an online form to: close your Self Assessment account ask to be removed from Self Assessment for a specific tax year You’ll need to provide your National Insurance number and your UTR number . If you cannot fill in the online form you can also contact HMRC by phone or post . If you’re no longer self-employed You also need to tell HMRC that you’ve stopped being self-employed . If you’ve already told HMRC that your self-employment has ended, HMRC may still ask you to send tax returns for future years. If you’ve checked and you do not need to send a tax return, you’ll need tell HMRC . What happens next You can track the progress of your form in your online account . HMRC will write to you and confirm if you need to send a return.

HM Revenue and Customs ( HMRC ) must receive your tax return and any money you owe by the deadline. The last tax year started on 6 April 2024 and ended on 5 April 2025. Deadline for telling HMRC you need to complete a return You must tell HMRC by 5 October if you need to complete a tax return and have not sent one before. You can tell HMRC by registering for Self Assessment . Deadline for submitting a paper return If you’re sending a paper tax return , you must submit it by midnight 31 October 2025. Deadline for submitting an online return If you’re sending an online tax return , you must submit it by midnight 31 January 2026. If you want HMRC to automatically collect tax you owe from your wages and pension, submit your online return by 30 December. Find out if you are eligible to pay this way . Deadlines for paying tax you owe You need to pay the tax you owe by midnight 31 January 2026. There’s usually a second payment deadline of 31 July if you make advance payments towards your bill (known as ‘ payments on account ’). You’ll usually pay a penalty if you’re late. You can appeal against a penalty if you have a reasonable excuse . To avoid a payment penalty, you can ‘estimate your Self Assessment tax bill’ before sending your tax return to: give you an idea of what your bill is likely to be allow you to budget and pay on time If you do not know your profit for the whole tax year You might not know what your profit will be for the whole tax year if, for example: your ‘accounting period’ ends at a different time to the end of the tax year your ‘accounting period’ is different to your ‘basis period’ you’re waiting for a valuation An ‘accounting period’ is the period which a business’s accounts are made up to (often 12 months) and gives the business year end. This can be different to the period used to identify the profits taxable in any particular tax year (also known as a ‘basis period’). If you do not know what your profit will be for the whole tax year before the reporting deadline, you should work out what it’s likely to be (known as ‘provisional figures’) and include those. You should tell HMRC that you’ve used provisional figures when you submit your return. When you find out what your profit was for the whole tax year, you’ll need to change your return . You have 12 months from the Self Assessment deadline to make these changes. If more tax is due, you’ll need to pay interest on the difference between your estimates and the final figures. The interest will be worked out from the original due date for payment. If you have overpaid tax then you’ll get interest paid to you. When the deadline is different HMRC must receive a paper tax return by 31 January if you’re a trustee of a registered pension scheme or a non-resident company. You cannot send a return online. HMRC might also email or write to you giving you a different deadline if they were late in sending out your return. Partnership returns if you have a company as a partner If your partnership’s accounting date is between 1 February and 5 April and one of your partners is a limited company, the deadline for: online returns is 12 months from the accounting date paper returns is 9 months from the accounting date 2023 to 2024 tax year and earlier The Self Assessment deadline for these tax years has passed. Send your tax return or payment as soon as possible - you’ll have to pay a penalty .

You’ll get a penalty if you need to complete a tax return and you: send your return late pay your tax bill late You can estimate your penalty for late Self Assessment tax returns and payments. If you register for Self Assessment late If you register after 5 October and do not pay all of your tax bill by 31 January, you’ll get a ‘failure to notify’ penalty. This penalty is based on the amount still left to pay and you’ll receive it within 12 months after HMRC receive your Self Assessment tax return. You can find more information on ‘failure to notify’ penalties . If you send your tax return late You’ll get the following late filing penalties: an initial £100 penalty after 3 months, additional daily penalties of £10 per day, up to a maximum of £900 after 6 months, a further penalty of 5% of the tax due or £300, whichever is greater after 12 months, another 5% or £300 charge, whichever is greater To avoid this, send your Self Assessment tax return as soon as possible. All partners will be charged a penalty if a partnership tax return is late. If you pay your tax late You’ll get penalties of 5% of the tax unpaid at: 30 days 6 months 12 months You’ll also be charged interest on the amount owed. To avoid this, pay your Self Assessment tax bill as soon as possible. Find out what happens if you do not respond to HMRC or refuse to pay what you owe. Paying a penalty You must pay within 30 days of the date on the penalty notice. Find out how to pay a penalty . If you disagree with a penalty If you have a reasonable excuse, you can appeal against a penalty .

If you need to change your return

You can make a change to a tax return after you filed it, for example because you made a mistake. Your bill will be updated based on what you report. You may have to pay more tax or be able to claim a refund . Updating your tax return You can correct a tax return within 12 months of the Self Assessment deadline , online or by sending another paper return. Example For the 2023 to 2024 tax year, you’ll usually need to change your return by 31 January 2026. If you miss the deadline or if you need to make a change to a return from an earlier tax year you’ll need to write to HMRC . Online tax returns You must wait 3 days (72 hours) after filing before updating your return. Sign in to your account . From ‘Your tax account’, choose ’Self Assessment account’. Choose ‘More Self Assessment details’. Choose ‘At a glance’ from the left-hand menu. Choose ‘Tax return options’. Choose the tax year for the return you want to amend. Go into the tax return, make the corrections and file it again. Paper tax returns For the main Self Assessment tax return you can: download the SA100 tax return form call HMRC and ask for the SA100 tax return form You can download all other forms and supplementary pages . You then need to send the corrected pages to the address on your Self Assessment paperwork. Write ‘amendment’ on each page and include your name and Unique Taxpayer Reference ( UTR ) - this is on previous tax returns or letters from HMRC . If you cannot find the address, you can send your corrections to: Self Assessment HM Revenue and Customs BX9 1AS If you used commercial software Contact the software provider for help correcting your tax return. Contact HMRC if your software is not able to make corrections. Changes to your bill You’ll see your amended bill straight away if you updated your tax return online. Within 3 days, your statement will also show: the difference from the old one, so you can see whether you owe more or less tax any interest To view this, sign in to your account and choose ‘View statements’ from the left-hand menu. If you’re owed tax You may be able to claim a tax refund . If you need to pay more tax Your updated bill will also show: the deadline for paying the effect on any payments on account you need to make If you sent an updated paper return HMRC will send you an updated bill. You can check when you can expect a reply from HMRC . They’ll pay any refund directly into your bank account, as long as you include your bank details on your tax return. If you’ve missed the deadline to change your return You must contact HMRC in writing if you need to make changes to your tax return more than 12 months after the Self Assessment deadline. This includes making a change to an earlier tax year. You’ll also need to write HMRC a letter to: report income you did not include in your tax return claim overpayment relief (if you think you’ve overpaid tax) You can claim overpayment relief up to 4 years after the end of the tax year it relates to. What to include You must include: the tax year you’re correcting why you think you’ve paid too much or little tax how much you think you’ve over or underpaid your signature (no one else can sign on your behalf) If you’re making an overpayment relief claim, you must also include in your letter: that you’re making a claim for overpayment relief if you’ve previously made an appeal for the same payment a signed declaration saying that the details you’ve given are ‘correct and complete to the best of your information and belief’ You also need to keep evidence that you’ve paid tax through Self Assessment for the relevant period as HMRC may ask for this at a later date. If you do not include all of this information your claim will be rejected. You can also tell HMRC how you want to be repaid in your letter.

Claiming a tax refund

You may be able to get a tax refund (also known as a ‘repayment’ or ‘rebate’) if you’ve paid too much tax. You can check how to claim a tax refund . You may not get a refund if you have tax due in the next 45 days (for example for a payment on account ). Instead, the money will be deducted from the tax you owe. If you’ve already claimed a tax refund You can check when you can expect a reply from HMRC about your claim. The status of your refund may show as ‘pending’ in your online tax account. This means that the refund has been created but still needs to be approved and paid.

If you need help with Self Assessment, you can: appoint someone to fill in and send your tax return, for example an accountant, friend or relative watch videos and join webinars ask HMRC ’s digital assistant contact HM Revenue and Customs ( HMRC ) for general Self Assessment enquiries get technical help with your online account Help filling in your return There’s introductory guidance on GOV.UK to: Capital Gains Tax if you’ve sold certain things like property or shares expenses if you’re an employee or self-employed High Income Child Benefit Charge if your income is over the threshold tax on income from renting property tax on savings interest tax on income from abroad - or on your UK income if you live abroad Guidance notes and helpsheets You can also read guidance in: the notes for each section of the tax return, for example ‘ UK property notes ’ if you’re completing that section HMRC ’s Self Assessment helpsheets

Returns for someone who has died

If you’re the ‘personal representative’ (an executor or administrator) for someone who has died, you might need to complete: a Self Assessment tax return for income the person earned before they died a separate Self Assessment tax return for income the ‘estate’ generated after the person died A personal representative is legally responsible for dealing with the deceased’s money, property and possessions (their estate). If you have not already told HMRC about a death you must do this as soon as possible. Use the Tell Us Once service to let HMRC and other government organisations know about the death. Returns for income the person earned before they died HMRC will tell you if you need to fill in a Self Assessment tax return for the person who has died. If you do, they’ll send you a form to complete and return. You’ll usually need details of the deceased’s bank and savings accounts, for example: bank statements building society pass books dividend vouchers National Savings bonds or certificates If the deceased was employed you’ll usually need: a P45 from their employer - if the return is for the tax year they died a P60 from their employer - if the return is for a tax year before the tax year they died details of any expenses paid by the employer - for example company cars, health insurance, travel expenses or childcare If the deceased was receiving a pension you’ll usually need: a final statement from their pension provider - if the return is for the tax year they died an end of year certificate from their pension provider - if the return is for a tax year before the tax year they died confirmation of any state pension You’ll also need details of any other income they had, for example if they rented out property or ran their own business. Contact HMRC’s Bereavement helpline if you need help completing a return for someone who has died or if you cannot find their records. Sending the return Send the completed Self Assessment form by post . The return must reach HMRC by the date given in the letter you received with the form. You can hire a professional (such as an accountant) to help you submit a tax return on behalf of the deceased. Returns for income the estate generated after the person died If the estate generates any new income after the death , you may also need to do both of the following: register with HMRC send a separate tax return on behalf of the estate You must check if you need to tell HMRC about the estate’s income .

Self Assessment tax returns

Q: Registering for Self Assessment

You must register for Self Assessment by 5 October if you need to complete a tax return and you have not sent one before. Check how to register for Self Assessment . If you’re new to Self Assessment, you’ll need to keep records (for example bank statements or receipts) so you can fill in your tax return correctly. Preparing for your tax bill You’ll need to pay your tax bill by 31 January. To prepare, once you’ve registered you can: estimate how much tax you might need to pay set up monthly or weekly payments to help you budget for your bill send your tax return any time after 5 April - doing it earlier means you’ll know what you owe

Overview

Self Assessment is a system HM Revenue and Customs (HMRC) uses to collect Income Tax.

Tax is usually deducted automatically from wages and pensions. People and businesses with other income must report it in a Self Assessment tax return.

If you need to send a Self Assessment tax return, fill it in after the end of the tax year (5 April) it applies to.

You must send a return if HMRC asks you to.

You may have to pay interest and a penalty if you do not file and pay on time.

This guide is also available in Welsh (Cymraeg).

Sending your return

You can file your Self Assessment tax return online.

If you need a paper form you can:

Deadlines

Send your tax return by the deadline.

You must tell HMRC by 5 October if you need to complete a tax return and you have not sent one before. You could be fined if you do not.

You can tell HMRC by registering for Self Assessment. Check how to register for Self Assessment.

Filling in your return

You need to keep records (for example bank statements or receipts) so you can fill in your tax return correctly.

You can get help filling in your return.

Paying your bill

HMRC will calculate what you owe based on what you report.

Pay your Self Assessment bill by 31 January.

How much tax you pay will depend on the Income Tax band you’re in. There’s a different rate for Capital Gains Tax if you need to pay it, for example you sell shares or a second home.

View a printable version of the whole guide

Self Assessment tax returns

Overview

Sending your return

Deadlines

Filling in your return

Paying your bill

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Self Assessment tax returns

Overview

Sending your return

Deadlines

Filling in your return

Paying your bill

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