Self Assessment FAQs

1. What is a self-assessment tax return?
2. How do I know if I need to complete a self-assessment tax return?
3. How and when do I register for self-assessment if I meet the above criteria?
4. When is the deadline for submitting my self-assessment tax return?
5. What information do I need to gather before completing my self assessment tax return?
6. What records should I keep and for how long do I keep them?
7. Can I use accounting software to complete my self-assessment tax return?
8. Are there any penalties or fines if I miss the deadline for submitting my self-assessment tax return?
9. How and when do I pay my tax liability after completing my self-assessment tax return?10. Should I appoint a Chartered Accountant to assist me with my self-assessment?
10. Should I appoint a Chartered Accountant to assist me with my self-assessment?

1. What is a self-assessment tax return?

A self-assessment tax return is a form used to report an individual’s income, gains and other financially relevant details to HMRC each tax year. The word self-assessment means that the individual (AKA taxpayer) is responsible for completion and submission of the correct numbers each year to HMRC.

Some individuals choose to do this themselves but due to the complexities of completing this form, in the majority of cases they appoint an Accountant to do this on their behalf.

2. How do I know if I need to complete a self-assessment tax return?

You must send a tax return if any of the following apply to you

• you were self-employed as a ‘sole trader’ and earned more than £1,000 (before taking off anything you can claim tax relief on)
• you were a partner in a business partnership
• you had a total taxable income of more than £100,000 (See below for taxable income)
• you had to pay the High Income Child Benefit Charge (If you earn over £50,000, unless you have opted out)

You may also need to send a tax return if you have any untaxed income, such as:

• money from renting out a property (you are a Landlord)
• tips and commission
• income from savings, investments and dividends (Not ISA’s)
• foreign income
• you are a director of ltd company who receives more than £1,000 in dividends

Taxable Income

• money you earn from employment
• profits you make if you’re self-employed – including from services you sell through websites or apps
• some state benefits (Jobseekers Allowance, Carers Allowance, Employment Support Allowance, Bereavement Allowance)
• most pensions, including state pensions, company and personal pensions and retirement annuities
• rental income (unless you’re a live-in landlord and get less than the rent a room limit)
• benefits you get from your job (P11d)
• income from a trust
• interest on savings over your savings allowance (£1,000 if you are a 20% basic rate taxpayer, £500 if you are a 40% higher rate taxpayer, £0 if you are a 45% additional rate taxpayer) – ISA’s are excluded from this.

3. How and when do I register for self-assessment if I meet the above criteria

You must usually register with HMRC for self-assessment by 5 October following the end of the tax year in which the income or gains first arose, otherwise penalties may be applicable.

You can register for self-assessment online with HMRC, once registered with HMRC they will send you a notification to complete a self-assessment tax return in April of each year then.

HMRC will also issue you with a 10 digit Unique Taxpayer Reference, commonly referred to as a UTR number. This number will need to be included on your self-assessment form when submitting to HMRC.

In the majority of circumstances individuals will appoint an Accountant to do this on their behalf.

4. When is the deadline for submitting my self-assessment tax return?

The deadline for submitting your self-assessment to HMRC is 31st Jan following the tax year for which you are submitting the tax return.

First of all you need to consider the tax year you are submitting a self-assessment for.

Examples

Tax Years run as follow 6th April to 5th April of each year (These dates are unique to the UK, everywhere else in the world generally has 1st Jan to 31st Dec with a couple of exceptions)

So,

6th April 2021 to the 5th April 2022 – Submission deadline is 31st Jan 2023
6th April 2022 to the 5th April 2023 – Submission deadline is 31st Jan 2024

For each tax year you can submit your self-assessment tax return anytime after 6th April up the following 31st Jan. So you have a window of nearly 9 months to submit them.

5. What information do I need to gather before completing my self assessment tax return?

a. Personal Information:

• National Insurance number
• Unique Taxpayer Reference (UTR) – this is supplied to you by HMRC when you register for self-assessment

b. Income Sources:

• Details of employment income (P60, P45, or payslips)
• Self-employment income (invoices, expenses, and profit/loss statements)
• Rental income (details of rent received and expenses)
• Interest and dividends (bank and investment statements)
• Pension income (P60 or annual pension statement)
• Any other sources of income (e.g., dividends, capital gains)

c. Expenses:

• Records of business expenses (receipts, invoices)
• Expenses related to employment (if applicable)

e. Tax Deductions and Credits:

• Details of any tax deductions or credits you’re eligible for (e.g., Marriage Allowance, Blind Person’s Allowance)

e. Capital Gains:

• Information on any assets sold during the tax year
• Details of any losses you want to offset against gains

f. Benefits and State Support:

• Information about any benefits received (Jobseekers Allowance, Carers Allowance, Employment Support Allowance, Bereavement Allowance)

g. Pension Contributions:

• Information on pension contributions made during the tax year

h. Gift Aid Donations:

• Records of any charitable donations made under Gift Aid

i. Student Loan:

• If you have a student loan, details of repayments made and the type of student loan you have i.e. Type 1 or Type 2 or Postgraduate Loan.

j. Residence and Non-Residence Status:

• Information about your residence status if you have overseas income

k. Other Relevant Documents:

• Any other documents or records related to your financial situation

6. What records should I keep and for how long do I keep them?

You should keep any records that substantiate the figures you have included in your self-assessment tax return. Should HMRC ever enquire about your figures then they will ask you to provide evidence of how these figures have been calculated.

Any supporting records should be kept for a minimum of 6 years including the current year.

7. Can I use accounting software to complete my self-assessment tax return?

You can submit your self-assessment tax return on paper by downloading form SA100 but doing this presents you with a shorter timescale. Paper returns must be submitted by 31st Oct each year.

The paper form for doing this is incredibly onerous and complicated to do.

To submit your self-assessment tax return online you will need to purchase HMRC approved commercial software or alternatively sign up for a personal tax account with HMRC and submit it via their software online. However, as with trying to fill in the paper version this is incredibly onerous and complicated for any taxpayer to do and is not something we would recommend as it’s fraught with the potential for error.

8. Are there any penalties or fines if I miss the deadline for submitting my self-assessment tax return?

With all taxes if there is a deadline then there will be a penalty for missing that deadline.

For self-assessment there are two types of penalties that can be incurred, one if for filing you self-assessment late and one is for late payment of any taxes due – the penalties for these are shown below

For Late Filing – Deadline 31st Jan

1st Feb to 30th April – £100
1st May to 31st July – £10 for each day (In addition to the above)
1st Aug to 31st Jan (next year) – 5% of the tax due or £300 whichever is greater

For Late Payment – Deadline 31st Jan

30 days or more late 5% of tax due

Interest on Late Payment

If you are late paying your tax HMRC will charge you daily interest until the tax has been paid, this will be in additional to the penalty charges above

Note : If your tax liability is more than £1,000 then you will fall into the payment on account system which is explained below

9. How and when do I pay my tax liability after completing my self-assessment tax return?

The actual payment of your self-assessment tax is due by the 31st Jan each year and subject to the above penalty regime if you are late paying.

You can complete and submit your self-assessment at any time from the 6th April to the 31st Jan but do not have to pay any tax due until 31st Jan following the tax year you are completing and submitting for.

If when completing and submitting your self-assessment your tax liability is greater than £1,000 then you will fall into the payment on account system that requires you to make payments on account to HMRC for the year after the year you are submitting your self-assessment tax return for.

This part often catches taxpayers out so make sure you understand the rules surrounding it.

Initially when you first fall into the payment on account system it seems harsh as you are paying your full tax bill for the previous year then at the same time paying 50% of your subsequent tax bill (based on an estimate of the previous year’s earnings). The other 50% becomes due on the 31st July each year, then a balancing figure when your actual self-assessment tax return is done.

It’s a complicated system to follow but runs like this:

Tax Year	22/23	Tax Due	£1,200.00	Deadline	31st Jan 2024
Tax Year	23/24	Pay on A/C	£600 (50%)	Deadline	31st Jan 2024
Total Due			£1,800.00
Tax Year	23/24	Pay on A/C	£600.00	Deadline	31st July 2024

So at this point and by 31st July you have paid £1,200 towards your tax bill for 23/24 tax year.

You then complete your tax return for 23/24 and the following happens

Tax Year	23/24	Tax Due	£1,400.00	Deadline	31st Jan 2025
Tax Year	23/24	Tax Paid	(£1,200.00)	Deadline
Balance to pay	23/24	Owed	£200.00		31st Jan 2025
Tax Year	24/25	Pay on A/C	£700 (50%)	Deadline	31st Jan 2025
Total Due			£900.00
Tax Year	24/25	Pay on A/C	£700.00	Deadline	31st July 2025

Hereinafter the self-assessment tax return is completed and the process described above repeats itself.

Note: It is only when you enter the payment on account system for the first time that your first payment is 150% of the tax due, thereafter it should be approximately 50% every 6 months unless there has been significant variations in the tax due.

10. Should I appoint a Chartered Accountant to assist me with my self-assessment?

It is highly advisable to appoint a Chartered Accountant to complete and submit your self-assessment for you. Chartered Accountants have the relevant training, experience and knowledge to ensure that you self-assessment tax return is:

1. Completed on time
2. Accurate
3. Have commercial software to enable submission online
4. Provide advice and guidance on what needs to be reported
5. Provide advice and guidance on what claims and reliefs you can make to reduce your tax liabilities.
6. Help reduce taxes as well as your anxiety and stress over them.