Self-Assessment Tax Returns

What is a Self-Assessment tax return?

Who is required to complete a Self-Assessment tax return?

How to register for Self-Assessment and send in a tax return

What if I don’t need to send a tax return anymore?

Important Self-Assessment tax return deadlines to remember

What are the penalties that I must be aware of?

How can I amend a tax return?

Get assistance completing a Self-Assessment tax return

What is a Self-Assessment tax return?

The UK Government uses the Self-Assessment system to collect Income Tax from individuals and businesses with additional income beyond wages and pensions. If HM Revenue and Customs (HMRC) requests it, you must submit a tax return.

This is typically required after the tax year ends on April 5th. You can file your return online¹ or by requesting a paper form. Keeping accurate records is crucial to fill in your return properly. The deadline to submit your return and pay any tax owed is January 31st. If you miss this deadline, penalties may apply.

Who is required to complete a Self-Assessment tax return?

You must send a Self-Assessment tax return if you:

• were self-employed earning over £1,000,
• a partner in a business,
• had income over £150,000,
• or sold assets with a capital gain last tax year.

It’s also required if you have untaxed income from renting out property, earning tips, or having income from savings, investments, and dividends, including foreign income. Additionally, you can choose to submit a return to claim tax reliefs or prove self-employment status for benefits like Tax-Free Childcare or Maternity Allowance. The deadline to inform HMRC is October 5th if you’ve never sent a return before.

How to register for Self-Assessment and send in a tax return

To send a Self-Assessment tax return in the UK, you must first register² with HMRC if you haven’t previously submitted a return. Returns can be filed online or on paper. The deadline for online submissions is January 31st following the tax year end, and for paper submissions, it’s October 31st. You can also use commercial software for specific scenarios like partnerships or if you lived abroad. Keeping accurate records is essential for accurately completing your return.

What if I don’t need to send a tax return anymore?

If you no longer need to send a Self-Assessment tax return to HMRC, you must notify them. For instance, if you’ve stopped being self-employed or no longer have a rental property generating income, you should inform HMRC. Once they confirm, you won’t need to submit returns unless circumstances change again. If HMRC disagrees, and you haven’t submitted a return, you might face a penalty. You can communicate this change to HMRC through their online form³, digital assistant⁴, calling 0300 200 3310 between Monday to Friday from 8am till 6pm, or post using the address below.

Self Assessment
HM Revenue and Customs
BX9 1AS
United Kingdom

For questions on the process of informing HMRC about you no longer being self-employed, please contact our accountants for a free telephone consultation on 01332 926452 or by email using Info@accountsfirm.co.uk.

Important Self-Assessment tax return deadlines to remember

For Self-Assessment tax returns in the UK, it’s crucial to meet the following deadlines: notify HMRC by October 5th if you need to send a tax return; submit paper returns by October 31st; and online returns by January 31st following the tax year end. You must also pay any tax due by January 31st.

Example

For the tax year 6 April 2023 to 5 April 2024.

You must tell HMRC by 5 October 2024 if you need to complete a tax return and have not sent one before.

If you’re doing a paper tax return, you must submit it by midnight 31 October 2024.

If you’re doing an online tax return, you must submit it by midnight 31 January 2025.

You need to pay the tax you owe by midnight 31 January 2025.

There’s usually a second payment deadline of 31 July 2025 if you make advance payments towards your bill known as ‘”payments on account”.

If you’re eligible and wish for HMRC to automatically collect tax owed from your wages or pension, submit your online return by December 30th. For partnerships with a corporate partner and specific accounting dates, different deadlines apply. Late submissions can lead to penalties.

What are the penalties that I must be aware of?

If you miss the deadline for submitting your Self-Assessment tax return or paying your tax bill, you’ll face penalties. A late filing penalty starts at £100 if your return is up to 3 months overdue. Additional penalties accrue for longer delays. Interest is also charged on late payments. If you believe there are valid reasons for your delay, you can appeal against the penalty. This is critical for partnerships as well, where all partners can be penalised for late submissions.

How can I amend a tax return?

If you need to change your Self-Assessment tax return after filing, you can amend it online or by sending another paper return within 12 months of the deadline.

For online returns, wait 3 days after filing to update. For paper returns, send the amended forms with “amendment” written on each page. If changes affect the tax you owe, your bill will be updated accordingly.

Get assistance completing a Self-Assessment tax return

If you need help with your Self-Assessment tax return, there are several options available. You can appoint an accountant like us, friend, or relative to handle it for you. For specific inquiries or technical issues with your online account, you can contact our accountants by phone on 01332 926452 or email using Info@accountsfirm.co.uk.