Self Assessment Tax Return Deadline
2023 Tax return checklist

2023 Self Assessment Tax Return Checklist

Why Accurus for filing your Self Assessment Tax Return

January 31st is the deadline for online Self-Assessment Tax Return submissions, as well as payments for any amount owed. 

We are actively preparing self-assessment tax returns now for our clients to avoid the last minute rush. There are many reasons to have your self-assessment tax returns completed by Accurus Accountants and some of these are:

  • We know all the allowances and expenses that can be claimed for your employment or business and can minimise the tax payable.
  • We prepare trading accounts for sole traders, again ensuring that all allowances and expenses have been claimed.
  • We can advise property landlords to make all the applicable deductions to minimise the tax liability.
  • We advise those with more than one employment to check whether they should file a self-assessment return or make a claim to HMRC for overpayment of taxes. Often additional employers will process your payroll incorrectly leading to issues in future years.
  • We prepare more complicated forms for individuals and that not all the self-assessment forms are available online. Some of these additional forms can relate to overseas transactions, capital gains on selling properties, employed in more than one country, partially resident for part of a year etc. A correct disclosure now could save on more complicated HMRC investigations and penalties.

Filing your Self Assessment Tax Return – Summary Checklist

  1. A Unique Tax Reference (UTR) number is issued to you on registering for Self-Assessment. There are two types of UTR numbers; Personal and Company. If you are the director of your own limited company, you will have a company UTR for your corporation tax and a personal UTR for your personal tax. You will need to submit your self-assessment tax return with the relevant UTR. If you’ve misplaced your 10-digit UTR number, you can look it up
  2. Your National Insurance number.
  3. P60 (if you are a salaried worker, this will be the case if you receive a salary from your limited company) and P11d, if applicable.
  4. Any untaxed income (with supporting documents) for the 2018/20 tax period. This would include income from renting out a property, tips and commission earned, income from savings, investments and dividends and any foreign income.
  5. Details and supporting evidence of any income from self-employment in the 2019/20 period. This will be income earned outside of your limited company as a sole trade.
  6. Details and supporting records for any charitable donations made, and expenses that have been incurred in the previous tax year. This also includes pension contributions paid through personal tax

When you’re a sole trader, you and your small business are legally one. But if you turn your business into a limited company (this is also known as ‘incorporation’), the company becomes a separate legal entity from you. This legal separation can work as both an advantage and disadvantage of incorporation, as you’ll see.

Your 2023 Self Assessment Tax Return Checklist 



For all employments held during the tax year, you should have either a P60 or P45:

  • P60 – issued by your employer(s) at the end of the tax year (5 April) to detail your taxable income and tax deductions for that year. If you made student loan deductions, this figure will also be provided.

  • P45 – issued by your employer(s) when you leave a job during a tax year. Similar to the P60, it details your taxable income and tax deductions for that year. If you made student loan deductions you’ll also need to provide your payslips for the year at these aren’t included on your P45.

If you have received taxable benefits during the year that aren’t on your payslip your employer should provide you with a P11D:

  • P11D – issued by employer(s) at the end of the tax year (5 April) to report taxable benefits provided to you that aren’t taxed on your payslip. Examples of benefits provided by employers are company vehicles & private medical insurance. Your employer has until 6 July following the end of the tax year to provide you with your P11D. If you had two jobs during the year, you may have two P11Ds.


If you receive income from rental property, we will need the following documentation:

  • details of the property being let (date purchased, price paid, legal fees and other costs on purchase, mortgage taken out, improvements made to the property, history of dates lived in property and dates property let, whether it is furnished or unfurnished, expected current value)

  • Details of rental receipts during the tax year with any management fee paid split out separately

  • Details of all expenditure on the rental property during the year (Insurances, Service charge, Ground rent, Repairs and Maintenance, Capital improvements (e.g. new kitchen), Utilities paid, details of trips made to the property (miles), advertising costs or any other costs directly related to renting the property).

  • Mortgage statement showing the capital/interest repayment split for the property – you can request this from your bank if they have not sent you one.

  • If you sold your property during the year, we will also need the date sold, selling price, legal fees and other costs on sale.

If you rent a room in your house then we will need details of the income received during the tax year.


If you use online bookkeeping software, please notify us once your records are up to date and they are ready for review.

If you keep a spreadsheet, please email us your spreadsheet for the relevant period. 


Your bank should issue you with a statement for each bank account showing how much interest you received for the tax year or you can add up the amounts for each month. All interest should now be paid gross (no tax deducted).

You do not need to send us information about interest from cash ISAs, premium bond receipts or interest from NS&I tax-free products, namely Fixed Interest Savings Certificates and Index-linked Savings Certificates as these are not taxable.


If you hold personal investments that are not contained within an ISA, then you should provide us with the dividend vouchers for the tax year.

If you are a director of a Limited company we will review your dividends received as part of our accounts service. 


State pensions – these are paid on a 4 weekly basis. HMRC will normally send a letter annually explaining how much the pension is increasing to. You will need to provide us with this document or bank statements which show the payment figures for a 4 week period during the year.  

Private pensions  you should receive a P60 for this income which we will need.


Jobseeker’s allowance – is a benefit for people who are actively looking for work

Maternity allowance – you can claim maternity allowance as soon as you’ve been pregnant for 26 weeks. Payments can start 11 weeks before your baby is due.


Capital Gains Tax – if you sold any shares or other assets in the tax year, we will need a breakdown of what you sold, when you sold it and the amount you sold it for. We will also need the purchase date and price and any other costs associated with the asset.

Foreign income – if you are UK resident then you need to declare your worldwide income on your UK tax return. You’ll need to provide details of any foreign income received during the tax year including any foreign tax paid.

Other – if you have some other income not mentioned above then discuss this with us to see if it needs to be included on your tax return. If in doubt, it’s always better to double check.



If you personally pay for expenses related to your employment you may be able to claim additional tax relief. The most common examples of these are:

  • Mileage – if you receive less than 45p per mile for business mileage in your own vehicle from your employer, then we can usually reduce your tax liability. We will need the number of business miles travelled and the rate your employer reimbursed you.

  • Uniform Allowance – if your employer has a set dress code then you may be eligible to various reliefs including uniform and cleaning allowances – suits & ties are generally not allowed. Find out what flat rate expenses you can claim tax relief on by checking the standard amounts to cover clothing and tools.

  • Professional subscriptions – if your job requires you to hold a membership to a professional body (and your employer does not pay for this) then we can usually claim the cost of this and reduce your tax liability. We would need proof of payment (invoice and/or bank statement).


Personal pension contributions – if you contribute to a personal scheme, then you may be able to claim additional tax relief. You will need to provide:

  • The name of the provider

  • Your contract/membership number

  • The amounts and dates of the contributions.

Company pension contributions – there are two types of arrangements whereby your company makes pension contributions on your behalf:

  • After tax contribution – this scheme will be referred to as ‘relief at source’ in your pension documents. You may be able to claim additional tax relief on these contributions so you will need to provide us with your payslips for the full year (April to March).

  • Before tax contribution – this scheme will be referred to as ‘net pay’ in your pension documents. You have already received full tax relief on these contributions. We will only require information if you’ve exceeded the pension threshold (see details below in other information).

If you are unsure which arrangement your company uses then send us your most recent payslip and we can advise further.


If you invested in an Enterprise Investment Scheme (EIS/SEIS) then you will probably be able to receive tax relief. You should receive a certificate from HMRC (form SEIS3) for each investment and will need to pass this on to us.


If you made donations to a qualifying charity and claimed gift aid then you may be able to claim additional tax relief (if you are a higher rate taxpayer). We need the following details (a good tip is to login to your just giving account and print out your past donations):

  • Charity name

  • Donation date of donation

  • Donation amount

  • Gift aid claimed? Yes/No

Other Information


Please let us know if your circumstances have changed so we can update our records, this includes:

  • Name change

  • Marital status change

  • Address change

  • Change to number of dependents


We will need your tax coding notices from HMRC over the year. 


If you receive child benefit, are earning over £50,000 & when compared to your spouse, you’re the highest earner – we need to add this to your self-assessment tax return. Let us know when you started receiving child benefit, how much you’ve received and how many children you have.


If one spouse is below the higher rate threshold (£50,000 for 2020/21) and the other spouse is below the personal allowance (£12,500 for 2020/21) you can claim the marriage allowance – this will save you just over £200 in tax. We will need your partners details (i.e. name, national insurance number & date of marriage)


If you have less than £110,000 of taxable income per year, then you can contribute up to £40,000 per year into a pension scheme for tax relief purposes.

For every £2 of adjusted income (this is the income shown on your P60 plus your pension contributions) above £150,000 per annum, £1 of this allowance will be lost (up to a maximum reduction of £30,000). This means that some higher earners may only receive a pension allowance of £10,000 per year. There is also a lifetime allowance of £1,073,100 (2020/21)

Therefore where you earn more than £110,000, please provide us with details of your pension contributions (employer and employee) for the current year and the three previous years (you can normally bring forward unused allowances). You should receive annual statements from your providers.

Get it Right, Contact us now.

To ensure that you have the right information for your tax return and to minimise tax liabilities, please contact us at Accurus Accountants for an informal discussion.
Click here to contact us