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Do I Need to Register for Self Assessment Tax if I’m Not Self-Employed?

Updated: Dec 28, 2023

If you're in Self-Assessment, you must submit a tax return every year. You have to declare your income or capital gain and request any allowances or reliefs. A majority of people don't have to register with the Self-Assessment tax if they are not self-employed. However, there are some exceptions. We will explain how this could be applicable to you if you are Not Self-Employed.

In the UK, the Self Assessment tax system requires individuals and businesses to report their income and calculate their tax liabilities. While commonly associated with self-employment, there are situations where individuals not self-employed must also register for Self Assessment. Understanding these scenarios is crucial for UK taxpayers to ensure compliance and avoid potential fines.

What is a Self-Assessment Tax Return?

If you're self-employed or have other multiple sources of income you'll most likely have to file a self-assessment return for tax purposes. Self-assessment reports to HMRC what amount of money you've earned this year, along with other information regarding your financial situation, to ensure that HMRC will be able to calculate your tax liability or the national insurance (NI) you are liable for. This is also referred to as "filing your annual tax returns: and, you can also complete it online. The phrase "self-assessment" does not suggest that you need to do it all by yourself. You could hire a tax accountant to take care of all the tasks for you. A tax accountant is able to fill out the form accurately for you and help you minimize the amount of tax you need to pay by avoiding paying any unpaid taxes.

After you've filed your tax returns, HMRC will calculate the amount of tax to be paid. They will then send you your notice of assessment and you can check it through your online account at the government's website. Then You have the option of paying the tax, typically by debit card online or by post.

Recent Changes in Self-Assessment Criteria

As of May 2023, HM Revenue and Customs (HMRC) announced significant changes to the income threshold for filing a self-assessment tax return. Previously set at £100,000, the threshold has been raised to £150,000, effective from the 2023/24 tax year. This change potentially alters the landscape for many taxpayers, especially those with high incomes but not self-employed.

Who Needs to Register for Self-Assessment?

Registration for Self Assessment is not solely for self-employed individuals. Various other circumstances necessitate registering for Self Assessment using form SA1. These circumstances include:

  • Income from Land and Property in the UK: Individuals receiving rental or other income from property in the UK must register for Self Assessment.

  • Taxable Foreign Income: If you have income from abroad that is liable for UK tax, registration is required.

  • High Income with Child Benefit: Households with an adjusted net income over £50,000 and receiving Child Benefit payments must register.

  • Yearly Income over £100,000: Regardless of the source, an annual income exceeding £100,000 triggers the need for registration.

  • Income from Trusts or Settlements: Receiving income from a trust or a settlement also requires Self Assessment registration.

  • Untaxed Income Not Collected Through PAYE: If you have untaxed income that cannot be collected via your PAYE tax code, you must register.

  • Capital Gains Tax Liabilities: Individuals with Capital Gains Tax to pay are also required to register​​.

Importance of Timely Registration

The deadline for registering for Self Assessment is a critical date to keep in mind. If you fall into any of the above categories or other situations requiring a tax return, you must register by 5 October following the end of the tax year for which you need to file a return. For instance, for the tax year 2022 to 2023, the registration deadline would be 5 October 2023​.

Reactivating an Existing Account

For those who have previously registered for Self Assessment but did not file a return in the last year, reactivation of your existing account is necessary. This step ensures that HMRC has your current details and knows to expect a tax return from you​.

Using HMRC's Online Tool

To determine if you need to send a tax return for the 2022 to 2023 tax year, HMRC offers an online tool. This tool can help clarify whether you fall under the criteria requiring registration for Self Assessment​.

Do I Need to Register for Self Assessment Tax if I’m Not Self-Employed?

Who Needs to Submit a Self-Assessment Tax if They’re Not Self-Employed?

HMRC requires information on any earnings you may receive to ensure that you pay the correct quantity of tax. Some earnings may come from self-employed people, and you may need to register for a Self Assessment tax to tell HMRC about any income you earn from a different source. This could be the case in the event that you:

● Earn any money from property or land that is located within the UK

● Receive taxable foreign income over £300

● Sell shares, property or any other asset that is susceptible to Capital Gains Tax

● Become a director of a company (even if you do not pay yourself dividends)

● Earn greater than £100,000 per year

● Get any income that isn't taxed and can't be collected by your tax code.

How Do I Register for Self Assessment Tax if I’m Not Self-Employed?

The process for registration to Self Assessment depends on whether you're self-employed or not. If you're not self-employed you're able to fill out and send the SA1 form via post or make an online application.

The Registration Process for Self Assessment in the UK

Step-by-Step Guide to Registering for Self Assessment

Registering for Self Assessment in the UK, especially for those not self-employed, is a process that requires attention to detail and adherence to specific steps. This section aims to guide UK taxpayers through this process, ensuring clarity and compliance.

1. Understanding the Need for Registration

Before beginning the registration process, it's important to establish whether you need to register for Self Assessment. As discussed earlier, various circumstances, such as receiving income from property, having foreign income, or an income exceeding certain thresholds, necessitate registration.

2. Using Form SA1

The specific form for individuals not self-employed is Form SA1. This form is used to register for Self Assessment for reasons other than self-employment​.

3. Gathering Necessary Information

Before filling out the form, ensure you have all necessary information on hand. This includes your full name, postal address (which can be outside of the UK), date of birth, daytime telephone number, and UK National Insurance number (if you have one). Additionally, you'll need to explain why you need to register for Self Assessment and the date this requirement started​.

4. Accessing the Government Gateway

To fill in and submit Form SA1 online, you'll need to access the Government Gateway. This requires either signing in with your existing user ID and password or using your email address to get a confirmation code for signing in. If you don't have a Government Gateway user ID, you can create one when you first sign in​.

5. Filling and Submitting Form SA1 Online or by Post

The form can be completed online, providing a quicker and more convenient method of submission. Alternatively, you can fill in, print, and post the form to HMRC, using the postal address shown on the form​.

Key Considerations During Registration

  • Timeliness: Ensure you register by 5 October following the end of the tax year for which you need to file a return. Late registration could lead to fines.

  • Accuracy of Information: Provide accurate and up-to-date information to avoid complications or delays in processing.

  • Understanding Your Tax Obligations: Registration for Self Assessment is the first step. It's essential to understand your tax obligations, including calculating and paying any tax owed.

When Should I Register?

If you didn't file your tax return last year then you'll need to register to participate in Self Assessment by 5th October following the conclusion of that tax period you have to file the tax return for. The first tax return you file is due on 31st January of the next calendar year if you file online. The deadline is October 31st for the following year, paper tax return.

What Happens When I Sign Up With Self Assessment?

HMRC will issue you a Unique Taxpayer Reference (UTR). You will also be notified each time your tax return is due. If your situation has changed and you are no longer required to file your tax return, inform HMRC as quickly as you can. When you're the first to register for the HMRC web-based services (which you'll be using to prepare the SA tax returns) you'll be provided with the activation number. This could take a few weeks to be delivered and you should make sure you sign up on time to file your tax return.

Consequences of Not Declaring Self Assessment in the UK

The Gravity of Non-Declaration

Not declaring income for Self Assessment in the UK is a serious matter, often classified as tax evasion. This crime can range from minor under-reporting to significant evasion of due taxes. Importantly, even unintentional failure to declare taxable income falls under this category. The repercussions of non-disclosure, whether deliberate or accidental, are substantial and varied, depending on the specifics of the case​.

Penalties for Non-Declaration

The most common consequence of not declaring income is a financial penalty. HM Revenue & Customs (HMRC) primarily focuses on recovering any unpaid taxes. In addition to repaying the owed tax, individuals can face fines up to 200% of the tax due. This punitive measure emphasizes the severity with which HMRC views non-compliance​.

Late Filing and Payment Penalties

Failure to meet deadlines for filing tax returns or making payments also results in penalties. A late filing penalty of £100 is charged if your tax return is up to three months late, with additional charges for longer delays or late tax bill payments. Interest is also charged on late payments, further increasing the financial burden​.

Risk of Prosecution and Imprisonment

In extreme cases, tax evasion can lead to criminal prosecution, with potential jail time. While sentences for tax evasion generally do not exceed seven years, there's no upper limit, allowing for more severe punishments in particularly egregious cases​.

HMRC's Detection Methods

HMRC employs sophisticated methods to detect undeclared income. They use advanced software, like 'Connect', to analyze large datasets for inconsistencies indicative of tax evasion. HMRC can also initiate investigations based on suspicions about the accuracy of tax returns or tax credit applications. Their access to financial records from banks, insurance brokers, and various companies, including Airbnb and crypto exchanges, enhances their ability to uncover undeclared income​.

Non-declaration of income for Self Assessment in the UK is a matter taken very seriously by HMRC, with consequences ranging from financial penalties to potential imprisonment. Understanding the importance of declaring all taxable income and adhering to Self Assessment deadlines is crucial for UK taxpayers. Failure to comply not only risks significant financial penalties but also the possibility of criminal prosecution. It's imperative for individuals to be thorough and accurate in their tax affairs, ensuring all relevant income is declared to HMRC to avoid these severe consequences.

How HMRC Detects Those Who Don't Declare Self-Assessment

Connect: HMRC's Digital Sleuth

The cornerstone of HMRC's strategy for detecting undeclared income is a sophisticated software system known as Connect. Launched in 2010, Connect is designed to analyze massive amounts of data, uncovering discrepancies between declared income and actual financial status. This system can identify patterns and associations in data that may initially appear unrelated, helping to reveal instances of tax evasion. For example, if your lifestyle expenditures exceed what you report as income, Connect can flag this inconsistency, potentially triggering an investigation​​​.

Wide-Ranging Data Sources

Connect integrates information from various sources, significantly enhancing HMRC's ability to detect undeclared income. These sources include:

  • Government departments and agencies like the DVLA, DWP, Land Registry, Border Agency, and Companies House.

  • Tax returns, including income tax, VAT, corporation tax, and PAYE.

  • Financial records from banks, building societies, online payment providers, credit card accounts, credit reference agencies, and crypto asset platforms.

  • Information from international financial records through global initiatives against tax havens.

  • Online sales and property websites, such as Amazon, eBay, Airbnb, Rightmove, and Zoopla.

  • Social media platforms, including Facebook, Instagram, LinkedIn, and Twitter.

  • Other peripheral sources like flight sales, passenger manifests, the Charities Commission, and even Google Earth​​.

HMRC's Proactive Campaigns and Public Involvement

HMRC actively searches for non-registered businesses and unreported income. This includes specific campaigns targeting particular industry sectors to uncover undeclared business activities and moonlighting. HMRC also encourages public involvement through the Tax Evasion hotline, where individuals can anonymously report suspected tax evasion. These efforts, combined with the extensive use of Connect, create a formidable detection network​​​.

Legal Powers and Consequences

HMRC has extensive legal powers to gather information. This includes details of debit and credit card sales and online selling activities. In cases of tax evasion, HMRC can impose penalties up to 100% of the owed tax, with interest on unpaid taxes adding to the financial burden. In severe cases, HMRC may even resort to using the Proceeds of Crime Act against individuals, significantly increasing the cost of tax evasion. It's worth noting that although the number of prosecutions for tax evasion is relatively small, HMRC expects this to rise, emphasizing the increasing risk of non-compliance​.

In summary, HMRC employs a multi-faceted approach to detect those who don't declare self assessment in the UK. The use of sophisticated software like Connect, combined with a variety of data sources, public involvement, and proactive campaigns, creates a robust system for uncovering undeclared income. The consequences of being caught can be severe, including heavy financial penalties and, in extreme cases, legal prosecution. This comprehensive detection strategy underscores the importance of complete and accurate income declaration for all UK taxpayers.

Why You Should Hire a Tax Accountant for Self-Assessment

Why You Should Hire a Tax Accountant for Self-Assessment?

Expertise in Tax Laws and Regulations

One of the primary benefits of hiring a tax accountant is their expertise in the intricate and often complex UK tax system. Accountants possess in-depth knowledge of tax laws, allowances, and reliefs, which can be crucial in optimizing your tax position and avoiding potential pitfalls. This expertise is especially beneficial for those with complicated financial situations or unique tax considerations​.

Time Savings and Efficiency

Completing a self-assessment tax return can be a time-consuming task, particularly for those with limited experience or complex financial circumstances. A tax accountant can significantly reduce the time you spend on this process by handling the entire task on your behalf. This allows you to focus on other important aspects of your life or business without the burden of tax preparation​​​.

Ensuring Accuracy and Compliance

Tax accountants are trained to prepare accurate and compliant tax returns, minimizing the risk of errors that could result in additional tax liabilities, penalties, or interest charges. Staying compliant with tax laws and regulations is crucial, and even small mistakes can lead to costly consequences. An accountant's expertise in this area ensures that your tax return is both compliant and free from errors​​​.

Representation and Support

In the event of a tax investigation or dispute with HMRC, having an accountant can be invaluable. They can act as your representative, providing support, advice, and guidance throughout the process. This representation can be crucial in navigating the complexities of tax investigations and disputes​.

Ongoing Financial Advice

Many accountants offer more than just tax return services. They can provide financial planning and business advice, helping you make informed decisions and improve your overall financial health. This ongoing support can be particularly beneficial for business owners and self-employed individuals​.

Never Missing Deadlines

With a tax accountant, the risk of missing important HMRC deadlines is significantly reduced. Accountants diligently track all key registration and filing dates, ensuring that every deadline is met. This not only helps avoid penalties but also keeps your financial affairs in good order​.

Tax Efficiency

Accountants can help maximize your financial efficiency by ensuring you're claiming every allowable expense and taking advantage of all available tax reliefs. Their knowledge and expertise often uncover hidden savings, leading to potentially significant financial gains​.

Stress Reduction

Dealing with tax returns can be stressful, particularly when trying to navigate the UK's complicated tax system. An accountant can alleviate this stress by handling all the intricate administrative tasks associated with filing your return, thus allowing you to avoid the anxiety associated with tax preparation​.

Identifying Future Money-Saving Opportunities

A good accountant is not just a tax-time ally but a year-round consultant. They keep you informed about cost-saving opportunities, provide tips for business growth, and keep you updated on changing tax regulations. Their proactive advice can be instrumental in shaping your business's financial future​.


While there are numerous benefits to hiring a tax accountant, it is important to consider potential drawbacks such as cost, loss of control over personal finances, and the risk of hiring an unqualified professional. These factors should be weighed against the benefits to determine if hiring an accountant is the right decision for your specific situation​.

In conclusion, hiring a tax accountant for self assessment in the UK offers numerous advantages, from expert guidance and time savings to ensuring accuracy and compliance with tax laws. Their ongoing support and financial advice can be invaluable in managing your financial affairs effectively. However, it's essential to carefully consider the costs and ensure you engage a certified and reputable professional to realize these benefits fully.

Need Help?

Self-assessment is simple for those whose financial issues are easy and who know the basics of what you're doing. But, it can be a lengthy process and you could be paying more taxes than is necessary when you're not certain of the tax benefits and costs you could be entitled to. In the worst case, mistakes could result in penalties. So, with more complicated accounts, it's recommended to employ a tax accountant to help you with your tax returns. "Pro Tax Accountant" has a team of specialists who can assist you with your Tax Self-Assessment. Contact us now!


Q1: Do I need to register for Self Assessment if I have foreign income?

A: Yes, if you have taxable foreign income over £300, you need to register for Self Assessment.

Q2: Is it necessary to register for Self Assessment if I am a company director? A: Yes, becoming a director of a company, even if you do not pay yourself dividends, requires you to register for Self Assessment.

Q3: What if I receive income from a trust or settlement?

A: If you receive yearly income from a trust or settlement, you must register for Self Assessment.

Q4: How do I register for Self Assessment if I'm not self-employed? A: If you're not self-employed, you can either complete and submit a SA1 form by post, or register online, which is faster​.

Q5: When should I register for Self Assessment?

A: If you didn’t send a tax return last year, you need to register by 5th October following the end of the tax year you need to submit a return for​.

Q6: What happens after I register for Self Assessment? A: After registering, HMRC will send you a Unique Taxpayer Reference (UTR). You'll also receive reminders for your tax return due dates​.

Q7: What information is needed to complete my tax return? A: You'll need details of all your taxable income and gains for the year, including self-employment income, property income, and employment and pension income​.

Q8: Can I amend my Self Assessment tax return after submitting it?

A: Yes, you can amend your return any number of times before the amendment deadline, which depends on when HMRC asked you to file the return​.

Q9: When do I pay the tax due for Self Assessment?

A: Self Assessment payments are usually due by 31 January following the end of the tax year. Some taxpayers may need to make payments on account towards their annual bill​.

Q10: Can I pay my tax in advance?

A: Yes, you can set up a Budget Payment Plan with HMRC to pay your tax weekly or monthly in advance by direct debit​.

Q11: What if I have untaxed income that can’t be collected through my PAYE tax code?

A: If you get untaxed income that cannot be collected through your PAYE tax code, you need to register for Self Assessment.

Q12: Is it mandatory to register for Self Assessment if my income is over £100,000? A: Yes, if your yearly income exceeds £100,000, you must register for Self Assessment.

Q13: What if I have Capital Gains Tax to pay?

A: If you have Capital Gains Tax to pay, you are required to register for Self Assessment.

Q14: Do I need to register if I receive income from land and property in the UK? A: Yes, if you receive income from land or property in the UK, you need to register for Self Assessment.

Q15: How does the online registration process differ from postal registration? A: The online registration process tends to be faster and more convenient compared to submitting a SA1 form by post.

Q16: What is the deadline for submitting a paper tax return?

A: The deadline for submitting a paper tax return is 31st October of the same year.

Q17: How do I receive my Unique Taxpayer Reference (UTR) number?

A: HMRC will send you your UTR number after you register for Self Assessment.

Q18: What should I do if my financial situation changes and I no longer need to submit a Self Assessment tax return?

A: If your situation changes and you no longer need to submit a Self Assessment tax return, you should inform HMRC as soon as possible.

Q19: Are there any penalties for failing to register for Self Assessment?

A: Yes, failing to register for Self Assessment by the required deadline can result in penalties.

Q20: If I have previously registered for Self Assessment, do I need to register again?

A: If you have registered before and did not send a tax return last year, you may need to reactivate your existing account rather than registering again​.



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