How to Register for Self Assessment

If you're self-employed, earn income outside of a PAYE job, or have complex tax affairs, you’ll likely need to register for Self Assessment to pay your tax. The Self Assessment system allows you to report your income to HM Revenue and Customs (HMRC) and pay any taxes due. Registering for Self Assessment is a straightforward process, but it’s essential to understand the steps and deadlines to avoid penalties.

Self Assessment is a method by which individuals and businesses report their income to HMRC if their income is not taxed at the source. This includes the self-employed, landlords with rental income, and people who receive dividends, interest, or income from abroad.

When you submit a Self Assessment tax return, you disclose your income, claim any allowances or expenses, and pay any Income Tax or National Insurance Contributions (NICs) due for the tax year.

Who Needs to Register for Self Assessment?

You need to register for Self Assessment if you:

• Are self-employed or a sole trader earning more than £1,000 from your business

• Have rental income from a property (more than £1,000 a year)

• Earn dividends from investments that exceed your dividend allowance

• Have savings or investment income over £1,000

• Have income from a second job or freelance work

• Need to report Capital Gains Tax on profits from selling property, shares, or assets

• Receive foreign income

• Are a partner in a business partnership

• Are a trustee

• Want to claim tax relief on your pension contributions or charitable donations

• Earn more than £100,000 a year

If you’re unsure whether you need to register for Self Assessment, you can use HMRC’s online tool to check.

How to Register for Self Assessment

1. Registering as Self-Employed or a Sole Trader

If you are self-employed or a sole trader, you need to register with HMRC for both Self Assessment and Class 2 National Insurance Contributions (NICs). You can register using HMRC’s online services.

• Visit the Gov.uk website and select Register for Self Assessment.

• You will need to provide personal details, including your name, address, National Insurance number, contact details, and business information.

• HMRC will send you a Unique Taxpayer Reference (UTR) number by post. This number is essential for all tax filings.

• Once you receive your UTR, set up an HMRC online account to file your returns.

If you’ve already been registered for Self Assessment in previous years, you only need to re-register if you’ve stopped and restarted self-employment.

2. Registering as a Partner in a Business Partnership

If you’re a partner in a business partnership, you will need to register separately for Self Assessment as an individual, while the partnership itself must also be registered. The nominated partner will complete the partnership tax return, and each partner is responsible for completing their individual tax return.

• For the partnership: You can register using the SA400 form.

• For individual partners: You can register online via the Gov.uk portal, and each partner will receive a UTR number for their personal tax returns.

3. Registering as a Landlord

If you earn more than £1,000 per year in rental income, you must declare this through Self Assessment. You can register online in a similar way to self-employed individuals.

• Tip: Keep detailed records of all your rental income and expenses, as you’ll need to include these in your tax return.

4. Registering as a Company Director

Company directors are usually required to file Self Assessment tax returns, even if they don’t receive a salary. If you’ve been appointed as a director, you’ll need to register for Self Assessment.

• Register online through your HMRC account or use the SA1 form if you’re not self-employed.

Deadlines for Registering

It’s important to register for Self Assessment before the relevant deadline to avoid penalties. The main deadline to remember is:

• 5 October after the end of the tax year in which you need to file a return.

For example, if you started earning self-employment income during the 2023/24 tax year (6 April 2023 – 5 April 2024), you need to register by 5 October 2024.

What Happens After You Register?

Once you register for Self Assessment, HMRC will:

1. Send you a Unique Taxpayer Reference (UTR) by post, which you will need for all future tax returns.

2. Issue a Self Assessment tax return form or notify you to complete your return online through your HMRC account.

3. Notify you of any payment on account amounts due. Payments on account are advance payments towards your next year’s tax bill.

How to Complete Your Self Assessment

After registering, you must file your Self Assessment tax return each year. The tax year runs from 6 April to 5 April, and the deadline for online filing is 31 January following the tax year (e.g. 31 January 2025 for the 2023/24 tax year).

You can submit your Self Assessment online by logging into your HMRC account. You will need to declare all your income, claim any allowances and reliefs, and submit any necessary documentation.

What Happens If You Miss the Registration Deadline?

If you miss the registration deadline (5 October), you should still register as soon as possible. You may be subject to penalties from HMRC if you file your return late or fail to pay your tax on time.

Paying Your Self Assessment Tax Bill

After you file your Self Assessment, HMRC will calculate how much tax and National Insurance you owe. You must pay any tax due by 31 January. If you need to make a payment on account, your first payment will also be due on this date, with the second payment due on 31 July.

You can pay your tax bill online, through Direct Debit, by bank transfer, or by cheque. For more detailed guidance on paying your Self Assessment tax, you can refer to our separate article on how to pay Self Assessment tax.

Conclusion

Registering for Self Assessment is a necessary step if you’re self-employed or have additional income that isn’t taxed through PAYE. The process is straightforward but must be completed by the 5 October deadline to avoid penalties. Once registered, you’ll need to file your tax return online by 31 January and pay any taxes due.

By following the correct procedures and keeping track of your income and expenses, you can ensure that your Self Assessment process runs smoothly each year. If you’re unsure whether you need to register or need assistance with your tax return, consult an accountant or tax advisor for help.