How to Register for Self Assessment Tax Return Using HMRC SA1 Form

• Self-assessment is the UK system for collecting income tax and national insurance contributions.
• Use form SA1 to register with HMRC for Self Assessment for any reason other than self-employment, and the self assessment tax return form SA100 self-assessment to report all your taxable income sources, claim reliefs/allowances and calculate your final tax liability for the year.
• You are considered ‘not self-employed’ and must file your self assessment tax return if you have an untaxed income that HMRC cannot collect through your PAYE tax code, such as rental, commissions, saving interest or investment income.
• Company directors and shareholders are not self-employed and must register for self-assessment to declare dividends (above £500), benefits, and expenses. Solo traders and partners in an LLP with earnings above £1,000 are considered self-employed and must register for self-assessment to report income, expenses, and drawings.

What does it mean to be ‘not self-employed’?

Being ‘not self-employed’ means your total income includes untaxed sources that cannot be collected using your PAYE tax code. As a result, you must register for self-assessment using form SA1.

Examples of such individuals include those who receive —

• income from land and property in the UK
• taxable foreign income
• An adjusted net income over £50,000, and you or your partner carry on receiving Child Benefit payments
• yearly income over £150,000
• annual income from a trust or settlement
• untaxed income that cannot be collected through your PAYE tax code
• Capital Gains and need to pay tax on the same.

I am not self-employed. Should I still register for a self assessment tax return?

Understanding your Self Assessment obligations as a company owner or director is crucial. Here is a clear breakdown of when registration is necessary —

No need to send a self assessment online if:

• You are a company director or shareholder; your only income is a salary taxed via PAYE, and you have no other untaxed income or benefits.

You must register for self assessment if you:

• Have untaxed income, income from overseas sources (including pensions), a partner in a business partnership, are liable to the High Income Child Benefit Charge, or are a self-employed individual with gross income over £1,000.
• Are an off-payroll worker (contractor) with a Student Loan to repay.
• Are a high earner with a net income taxed through PAYE that exceeds £150,000

Why do I need to file a tax return online or by post if I am not self-employed?

If you are a company director or shareholder who receives additional untaxed income, you will file self assessment tax returns because of the following —

• Expenses — There are two things you should know about expenses. The first is that expenses reduce taxable income, while the second is that HMRC may consider an expense a taxable benefit if used for personal use.
• Dividends — For the 2024/25 financial year, dividend income below £500 is tax-free. If your dividend income is between £501 and £10,000, you may choose to have the tax deducted under PAYE instead of filing a self-assessment. However, you must send a return if your dividend income exceeds £10,000.
  • Dividends impact a director/shareholder's income in two ways. First, they can push the individual into a higher tax band. Second, reporting dividends ensures the correct tax rate is applied.
  • The tax-free dividend allowance has been reduced from £1,000 to £500 starting from the 2024/25 tax year. However, for 2023/24, the allowance remains at £1,000.
• Benefits — Benefits are taxable income and must be reported in two ways: through form P11D, where the company reports benefits provided to employees and directors, and through self-assessment, where directors/shareholders report benefits received.
  • Benefits can affect an individual's tax rate by potentially moving them into a higher tax band.
  • Some benefits, such as director loans, have specific tax rules. Taxable benefits include company cars, private medical insurance, and low-interest loans.

See also: What Is a Limited Company?

Why do I need to complete a self assessment return if I am employed?

A Sole trader or a partner in a limited liability partnership (llp) is considered self-employed for tax purposes and is, therefore, required to file tax returns to avoid fines and penalties. This ensures that all income, benefits, and expenses are accurately reported and taxed.

Partners in a limited liability partnership (LLP)

Partner tax obligations and benefits that must be managed through self-assessment include —

• Partnership Income — LLPs are tax transparent, meaning that each partner is taxed individually and must report their share of profits or losses in their tax return. LLP income is treated as self employment income.
• Expenses — Partners can claim business-related expenses and capital allowances against their profit share, which reduces their taxable income and must be reported on their self-assessment tax return online.
• Drawings — Money from the partnership (drawings) must be accounted for, and any tax implications must be reported.

Sole Traders

A solo trader’s tax obligations that must be managed through self-assessment include —

• Business Profits: They must register and declare their business profits or losses on their self-assessment tax return. The tax rates for the current year (2024/25) are as follows:
  • The first £12,570 of your profits is tax-free.
  • Profits between £12,571 and £50,270 are taxed at the basic rate of 20%.
  • Profits between £50,271 and £125,140 are taxed at the higher rate of 40%.
  • Profits above £125,140 are taxed at the top rate of 45%.

  Ensure you accurately report your earnings to meet your tax obligations.

• Expenses — Sole trader can deduct allowable business expenses from their taxable profits but report them when filing a tax return.
• Additional Income — Any other income, such as rental or investment returns, must also be reported.

How to register for self assessment with HMRC if you are not self employed.

To register online for self assessment if you’re not self-employed, follow the steps below.

• Complete Form SA1 to register for self assessment
• Provide basic information such as name, address, NINo, and the reason for registering (e.g. rental income).
• Submit it by post or using the government gateway online service.
• HMRC will issue you a UTR and an activation code (separately) within 10-21 days and set you up for Self Assessment.

If you already have a business tax account with HMRC sign in and add Self Assessment to your list of services. You’ll need a Government Gateway user ID and password.

What should I expect after I fill and submit the SA1 form online?

If you are not self-employed, use the registration form SA1 to enrol for self-assessment. You may not receive an email confirmation after completing and successfully submitting the form. However, there's no cause for concern if you've followed all the necessary steps and filed correctly.

HMRC may take up to 3 weeks to contact you with your taxpayer number, and this duration may extend during busy periods. You can use this tool to check when you can expect a reply.

How to file your self assessment online or send a return by post using form SA100

After obtaining your UTR number from HMRC, use the SA100 tax return form to send your tax return. You can either complete and send the form online or mail a physical copy to

• Self Assessment
• HM Revenue & Customs
• BX9 1AS
• United Kingdom

OR if you live outside the UK, send it to:

• HM Revenue & Customs
• Benton Park View
• Newcastle Upon Tyne
• NE98 1ZZ
• United Kingdom

Depending on your circumstances, you may also need to fill out supplementary pages with your tax return:

• SA101 – less common types of income, deductions and tax reliefs
• SA102 – employment income
• SA103 –self employment income if your annual business turnover is below the VAT threshold for the year.
• SA105 – UK property income
• SA106 – foreign income and gains
• SA108 – capital gains and losses

Whether you file online or by paper, the information you fill out remains the same. However, if you opt for online submission, you will get 3 extra months before the deadline. The deadline for submitting your tax return by post is October 31st, following the end of the tax year, while the deadline for online submissions is January 31st.

For example, for the 2023/2024 tax year:

• Register for Self Assessment by 5 October 2024
• Submit your paper tax return by midnight on 31 October 2024
• Submit your online tax return by midnight on 31 January 2025

Do I need a unique Taxpayer Reference (UTR) number to complete a tax return?

Yes, you do. A UTR number is a 10-digit unique identifier issued by HMRC to companies and individuals for tax purposes. If you don't already have a taxpayer reference, one will be issued when you register for self-assessment. You can find a lost UTR number in any correspondence from HMRC.

Please note that if you’re waiting for a unique taxpayer reference from HMRC to activate your online account and file your tax return, it may take up to 10 working days to receive it or up to 21 days if you are abroad.

2024 Filing Deadline and Other Due Dates

Knowing when and how to settle your Self-assessment tax bill is crucial. Here is a breakdown of key tax return dates.

• Register for self assessment by 5 October.
• Paper income tax filing deadline is 31 October, while online is 31 January.
• Income tax payment deadline is 31st January.
• A financial year begins on 6 April.
• 5 April is the end of the tax year.

See also: UK Tax Year Dates and Filing Deadlines

How can I manage my tax bill payments if I'm not self employed?

You have three main options for settling your tax bill —

• Full Payment by Deadline — You can wait until the deadline and make a one-time lump sum payment for the entire amount owed.
• Budget Payment Plan — Consider setting up a Budget Payment Plan with HMRC for a more manageable approach. This allows you to spread your tax bill across the year through weekly or monthly instalments.
• Payment on accounts — Make advance payments towards your next year’s tax bill, reducing the amount due at the end of the year.

Exploring Budget Payment Plans

• Budget Payment Plans can be established through your online Self-assessment tax account.
• Carefully assess your financial situation to determine if a payment plan best suits your needs.

Remember, late payments incur penalties. Opting for a Budget Payment Plan can help you avoid significant penalties by ensuring timely payments, even if you cannot pay the entire amount upfront.

What are payments on account?

If your income is over £1,000 and less than 80% of it is taxed at the source, HMRC may require you to pay payments on account, a payment made towards your next year's self-assessment tax bill.

What is the primary purpose of the HMRC app, and what services can you use it for?

The HMRC app offers a convenient way to access information about your taxes, NI status, tax credits, and benefits.

With the app, you can check your:

• Tax code
• National Insurance number
• Income and benefits
• Employment and income history from the past five years
• How much you will receive in tax credits and their payment dates
• Unique Taxpayer Reference (UTR) for Self Assessment
• How much Self Assessment tax you owe
• Child Benefit details
• State Pension forecast
• Any gaps in your NICs

Additionally, you can use the app to:

• Get an estimate of the tax you need to pay
• Make a Self Assessment payment
• Make a Simple Assessment payment
• Set reminders for Self Assessment payments
• Report changes and complete your tax credit renewal
• Access your Help to Save account
• Use the tax calculator to determine your take-home pay after deductions
• Track forms and letters you have sent to HMRC
• Claim a refund if you have overpaid tax
• Ask HMRC’s digital assistant for help and information
• Update your name and address
• Save your NINo to your digital wallet
• Check for gaps in your NICs and understand the benefits of paying them
• Check if you can make a payment for gaps in your NICs.
• Opt to be contacted by HMRC electronically instead of by letter

Can I use a commercial software for filing online returns?

Yes, you can use commercial software to send your returns online. Commercial software providers offer services for submitting tax returns and additional pages to HMRC. HMRC acknowledges and accepts returns filed using these software products.

Getting assistance with Self Assessment

Here is a breakdown of the various HMRC support resources available to help you —

• General Inquiries: Contact HMRC directly for any questions about Self Assessment.
• Learning Resources: Utilise HMRC's online resources, including informative videos, webinars, and helpful guides on different income types.
• Digital Assistant: HMRC's digital assistant can offer basic assistance with your online tax account.
• Technical Help: Are you encountering technical difficulties with your online account? HMRC provides dedicated technical support.
• Help Sheets: Download informative Self Assessment helpsheets from the HMRC website.

You should consider appointing a qualified accountant or tax agent for professional guidance. They can help you structure your income for optimal tax efficiency and benefit from claiming all the reliefs and allowances you are entitled to. They can also ensure accurate and timely filing of your tax return.