Facebook Twitter Linkedin Instagram Pinterest
Instant Quote
Call Me Back
common self assessment mistakes

What are the Most Common Self Assessment Mistakes?

04/03/2025Self Assessment Tax Returns

Most self-employed beginners make some common self-assessment mistakes that lead to penalties. Self-assessment tax return filling is a necessary step if you are self-employed in the UK. However, the most crucial thing is to ensure accuracy in filling out the self-assessment tax return to prevent the penalty by HMRC. In this article, you will not only know about the common self-assessment mistakes but also that their solution is also provided that ensures your business growth and success.

Talk to our best accountants and bookkeepers in the UK at CruseBurke. You will get instant help about common self-assessment mistakes.

What are the Common Self-Assessment Mistakes?

There are some common self-assessment mistakes that you must be aware of for running a business smoothly. Additionally, analyse the solution to all these errors that ensure the right alignment for standing out the business. Read them carefully and prevent yourself from penalty.

  1. Not Keeping Proper Records

The top mistake in tax filing is not keeping all records of income and expenses accurately. If you forget all the vital financial details, it may lead to incorrect tax filing. The cause of errors is that you may miss important information about the financial cases to add in the filing.

Strategies to adopt:

Following are some strategies enlisted for this mistake of tax filing:

  • Must use spreadsheet and accounting software for all the financial information.
  • Consistent and regular updating also helps you keep records of all earnings and expenses.
  • Hiring an accountant is also a good strategy to ensure the collection and recording of all financial data.

  1. Confusion about Allowable Expenses

Paying tax is affected due to misinterpretation of the valid business expenses by many self-employed. Simply incorrect claims of personal expenses lead to errors in the filling.

Strategies to adopt:

You can adopt these strategies for filling out the tax to prevent these types of errors.

  • You must be aware of all the expenses that HMRC allows.
  • If you are not sure about your expenses, go through the guidelines of the HMRC.
  • Record the expenses efficiently and go for consultation with an expert in financial management and tax filing.

  1. Missing Deadlines

Filing tax returns on time is very crucial because missing the deadline leads to penalties. Missing the deadlines is one of the most common self-assessment mistakes that causes you to pay extra charges and impact the business cash flow.

Strategies to adopt

The best strategies to fix this self-assessment mistake of missing deadline are the following:

  • Use a calendar to mark all the tax deadlines to never forget the tax submission date.
  • Reminders in advance for the tax filing dates also ensure that you fulfill the HMRC requirements deadlines.
  • Collaborate and build consensus with accountants to not miss the deadlines.

  1. Not Claiming Tax Relief and Allowances

Many self-employed individuals pay more tax because they are not aware of how to take advantage of the available tax reliefs and allowances. The tax liabilities can be reduced through two different ways: 1) pension contribution deduction and 2) inventory allowance. But due to the lack of knowledge about it and the uncertainty of their eligibility, it becomes the reason to overlook these advantages. Understanding these reliefs is important to manage all the finances and comply with the tax laws.

So, instead of overpaying, is it best to be aware of all the updates on tax reliefs provided by the HMRC?

Strategies to adopt

Preventing this mistake is very important for sustaining your financial cash flow in the business. For this, you should follow the below-mentioned tips that can prevent you from overpaying.

  • Keep updated about the new tax laws and regulations because every year, HMRC provides new tax reliefs and allowances.
  • Consultation with the expert individual helps you to save money and predict all the financial deductions accurately. Tax professionals can also help you to understand your financial situation and offer the best strategies for managing tax.

  1. Forgetting to Declare Other Income

Most people do not inform about other sources of income, such as investment, online earning, or second jobs; this tax leads to unavoidable tax bills and penalties. So, forgetting to declare multiple sources of income is also a common mistake while running businesses. Hence, all earnings from different sources, including a secondary job, investments, and online income, need to be reported to the government to prevent tax problems.

To stay compliant, first check what income needs to be reported based on HMRC guidelines. Using HMRC’s checking tool can help determine your tax obligations quickly and accurately. Keeping clear records of all earnings and consulting a tax professional when needed ensures you file correctly and avoid unnecessary fines. Proper tax reporting keeps your finances in order and stress-free.

Strategies to adopt:

To stay compliant and avoid this mistake, you should use these strategies:

  • Learn all the guidelines provided by HMRC to mention which source of income or not for fulfilling the government requirement.
  • Determination of tax obligation is crucial for this; use HMRC checking tools to ensure accuracy.
  • Consultation with the tax professionals and recording all the financial information help you in accurate filing.
  • Tax reporting on time is also considered the best approach that eliminates your stress regarding financial management.

  1. No Government Gateway User ID

A significant number of individuals overlook the necessity to sign up for Government Gateway accounts since they also lose their user IDs. Your inability to file the self-assessment tax return becomes inevitable once you do not have this account because delays near the deadline could earn you a penalty fee. Basically, the Government Gateway serves as an identity authentication system for HMRC services, where self-assessment functions among these services. A Government Gateway user ID is a necessary requirement for starting account setup.

You can register by visiting the HMRC website, where they will need your National Insurance number, your UK address, recent pay stubs or P60s and a supported UK passport. The activation code will be sent to your registered address through postal mail by HMRC, and the delivery may require up to 10 days.

Strategies to adopt:

If you forget to register for a Government Gateway account or lose your Government Gateway user ID, then use these strategies for management:

  • You can recover them on the GOV.UK website. In case you are not able to access your registered email, create a new account and wait for a new activation code.

  1. Losing your Unique Taxpayer Reference (UTR)

This is one of the most common mistakes made by many self-employed people, as this number is very crucial for first-time self-assessment filling. However, before 20 days of filing the tax deadline, you should have applied for the Unique Taxpayer Reference (UTR) number.

Strategies to adopt:

  • Checking past tax returns and HMRC letters helps you find your UTR number.
  • Moreover, you can also find it in payment reminders.

Conclusion

Consequently, it is very important to learn from the mistakes that most self-employed people make to take vital actions for the smooth running of your business. Steps you can take that prevent the common self-assessment mistakes include keeping detailed records, learning tax rules, and filling out tax returns on time. Moreover, seeking guidance and taking consultations from tax experts or accountants is also the best approach for the management of finances.

Reach out to our intelligent and clever-minded guys to get the answer to your queries in the UK, we will get to your answers quickly. We will help to decide how to deal with your tax implications.

Disclaimer: The information about the common self-assessment mistakes provided in this blog includes text and graphics of a general nature. It does not intend to disregard any professional advice.

 

Related post

self assessment registration for Directors
Self Assessment for Directors: Registration, Deadlines and Penalties

26/09/2025Self Assessment Tax Returns

Directors hold a key portfolio and are known for multitasking. Directors usually get a salary, dividends, and other perks. These bring tax duties. Here comes into play the self-assessment registration for directors, to streamline their tax matters. This may look complex, yet it is an easy task with the knowledge of the steps. With self-assessment registration for directors, you will avoid fines. In this guide, you’ll get to know the step-by-step process of Self Assessment registration for Directors. It helps you determine whether you need to register, and helps you obtain your Unique Taxpayer Reference (UTR). Talk to our best accountants and bookkeepers in the UK at CruseBurke. You will get instant help on how to register for self-assessment as a director. What is Self Assessment Registration? Self-assessment is the one that deals with your tax returns. Here, you report your earnings for a specific year, and HMRC uses them. You calculate tax owed, and you pay it to HMRC. Directors face different rules. You get a salary through PAYE. Your employer may deduct tax. However, if you receive dividends, these are not taxed at the time of payment, but you must still declare them on your self-assessment tax return. The directors who get an untaxed income, like dividends, have to make self-assessment registration with HMRC before 5 October. Keep a proper record of your dividend income. Along with the registration, directors need to file their tax return with HMRC before 31 January. Then why bother? Compliance builds trust and prevents penalties. Late filing costs £100. Interest adds up, also. Self-assessment enables you to claim reliefs. You offset expenses and reduce your tax bill. When a Director Has to Register a Self-Assessment? You need to register for Self Assessment when: You get dividends: You must file a tax return if you receive dividends over £10,000 in a tax year. Even if you receive a smaller amount, you will still have to pay tax on any dividends above the £500 tax-free allowance. You get other income that has not been taxed: This includes rental income from a property. You are a sole trader or partner as well as a director: This requires you to file a Self Assessment. HMRC asks you to: If HMRC sends you a notice to file a tax return, you must follow it. When to Register for Self Assessment? Timing is important for Self Assessment registration. You need to register by 5 October after the tax year when you earned untaxed income. The UK tax year runs from 6 April to 5 April the following year. For example, if you need to file a tax return for the 2024–2025 tax year (from 6 April 2024 to 5 April 2025), you will need to register by 5 October 2025. If you miss the deadline, HMRC could charge you a penalty. Hence, it’s best to register early to avoid any problems. A Step-by-Step Guide to Self-Assessment Registration for Directors Registering for Self Assessment is straightforward and can be done online. You’ll need to use the UK government website (gov.uk) to begin. If You Are New To Self Assessment 1. Gather your information: Before you start, have the following details ready: Your National Insurance number Your full name and address Your date of birth The date you became a director 2. Go online: Search for “Register for Self Assessment” on the Gov.uk website. 3. Create a Government Gateway account: If you don’t have one, you will be prompted to create a new Government Gateway account to access the service. 4. Register as a company director: During the process, you will be asked the reason for your registration. Select “You are a company director” and follow the on-screen instructions to provide the information you gathered in step 1. If You Are Already Registered For Self Assessment If you have filed a Self Assessment tax return before, there’s no need to register again. When you complete your annual tax return, you just need to include your directorship income and benefits. Get your UTR number Once you have completed the online process, HMRC will send you a letter containing your Unique Taxpayer Reference (UTR) number. This is a 10-digit number that identifies you for tax purposes. The letter usually arrives within 10 working days, though it can take longer. Once you have your UTR, you can create your online account using the Government Gateway and file your tax return. Create Your Online Profile You will have already created a Government Gateway account during the initial Self Assessment registration process. The purpose of this step is to add the Self Assessment service to your account now that you have your UTR. How to set up your online access: After you have completed your online registration, HMRC will send you a letter. The letter will contain your Unique Taxpayer Reference (UTR) number. Go to the Gov.uk website. And sign in to your Government Gateway account using the 12-digit Government Gateway User ID and password you created earlier. Once signed in, you will be able to add the Self Assessment service to your account. You will need to input your UTR number to link your tax reference to your online profile. HMRC will then send a separate activation code by post. This code is an extra security measure. Log back into your Government Gateway account and enter the activation code when prompted to complete the setup. Once activated, you can begin preparing and filing your Self Assessment tax return online. Common Errors to Avoid in ‘Self Assessment Registration for Directors’ Forgetting the registration deadline, which is 5 October. Missing the January 31st deadline for submitting your online tax return results in an immediate £100 penalty, even if you owe no tax. Forgetting to budget for and pay your second tax instalment by the July 31st deadline. Neglecting to declare income not taxed through your payroll (PAYE), such as rental income, freelance earnings, or capital gains from selling assets. Assuming dividends are tax-free. Dividends over the …

Read more
is there a P45 for self-employed
Is There a P45 for Self-Employed?

25/03/2024Business

Wondering about Is There a P45 for Self-Employed? Self-employment refers to running your own business and being solely responsible for its financial affairs. It is a form of job status that comes with various commitments and obligations. One of the most important duties is paying taxes and national insurance. In the UK, self-employed individuals are not issued a P45 form like PAYE employees. This article will provide you with everything you need to know about the requirements and process.   Our team of professional members loves to hear out your problems and find out the possible and suitable solutions quickly for small businesses’ accounting problems. Call us or email us today.   Self-employed vs PAYE Self-employed individuals may choose to work freelance or start their businesses. They can provide services directly to clients, or create products that they sell to customers. They are responsible for all aspects of their business, including taxes and accounting. On the other hand, employees work under an employer. Their earnings and national insurance contributions are typically deducted from their paycheck and paid by the employer. They are typically entitled to things like sick pay, maternity leave, and holiday pay. However, they do not have control over their working schedule and are bound by the terms of their contract.   Is There a P45 for Self-Employed? In the UK, self-employed individuals do not receive a P45. Instead, they are responsible for filing an HMRC Self-Assessment Tax Return and declaring their income and liability. This usually happens on an annual basis, although there are some exceptions. The HMRC will provide detailed information on the exact filing requirements and deadlines. Additionally, self-employed individuals have to make regular payments to HMRC to ensure their taxes and national insurance are paid. Here’s a basic summary of what self-employed individuals should know about tax and national insurance requirements in the UK: Self-employed individuals are responsible for reporting their income and liability to HMRC on an annual basis via Self Assessment Tax Returns. Self-employed individuals must also make regular payments throughout the year to cover taxes and national insurance. Self-employed individuals can take advantage of various deductions, including expenses and losses. To reduce their tax liability. It’s important to keep track of these deductions and know when and how to apply them.   What if I’m a PAYE Employee as Well as a Freelancer? If you’re a PAYE employee with a freelance side hustle in the UK, you’ll need to take careful consideration of both tax and national insurance obligations. In terms of tax, you’ll need to determine which tax regime you fall under. If you’re classified as a traditional part-time freelancer, you’ll only pay tax on your freelance income on top of your job income. However, if you’re considered a traditional full-time freelancer, then taxation will be applied differently. As a PAYE employee with a freelance side hustle in the UK, know the following factors: You must ensure you are paying the correct tax according to your income situation and employment status. If you fall into the low-income part-time freelancer category, you’ll only have to pay tax on your freelance income, but it will be added to your overall income and taxed at the same rate. If you’re a full-time freelancer, you will have to pay tax on your overall income.   What will Happen if I Switch from Self-Employment to Employment? If you are switching From Self-Employment to Employment in the UK, know the following points. Start by finding a suitable job and applying for it. Once you’ve secured an offer, it’s time to end your self-employment status. This includes ending any contracts or business arrangements, informing clients, and submitting a form to HMRC. Once your self-employment status has ended and you start your new job, you should submit your P45 form to your employer. This lets HMRC know that you’ve switched from self-employment to full-time employment. Your new employer will then send your details to HMRC. Who will assign you a new tax code and collect your tax based on that code? You’ll get a new pay slip from your employer. Which shows your income and deductions as per your new tax code. You’ll then receive a letter from HMRC confirming your employment status. This letter includes details of your new tax code and what to do next. Be sure to read it carefully and follow any instructions given. Your previous self-employment details will be deleted and replaced with your new employment details. This means that you won’t be able to claim any expenses or losses associated with your former business.   What if I’m No Longer Claiming Benefits to Start Work? If you’ve stopped claiming benefits to start work, you may need a P45 from your Previous Employer. To obtain the P45, you should contact your previous employer and request it. Make sure to provide them with your National Insurance number, the last date you worked with them, and the name of your new employer. If they have any other specific requirements, they’ll let you know. They will then provide you with the form, which you can give to your new employer. You should ensure that the P45 has all the correct information on it before submitting it to your new employer. This form will enable your new employer to adjust the amount of tax you pay on your income, ensuring that your taxes are calculated accurately. Be sure to keep a copy of the P45 for your records in case you need it in the future.   The Bottom Line Self-employment has its unique features, including tax and financial obligations. In the UK, self-employed individuals are not issued a P45 like PAYE employees. Although they have to file a self-assessment tax return and pay their taxes according to the prescribed guidelines. We hope these few minutes of reading will help you to develop a better understanding of whether is there a P45 for self-employed in the UK.   Reach out to our intelligent and clever-minded guys to …

Read more