Completing a Self-Assessment tax return can feel daunting, particularly if it is your first time or if your financial affairs have become more complex over the year. However, with the right preparation and a clear understanding of what is required, the process is far more manageable than it might appear. This guide walks you through everything you need to know to complete your UK Self-Assessment tax return accurately and on time.
Who Needs to Complete a Self-Assessment Tax Return?
You are required to complete a Self-Assessment tax return if you are:
- A self-employed sole trader
- A partner in a business partnership
- A director of a limited company
- Someone with untaxed income such as rental income, savings interest or foreign income
- Someone whose PAYE income exceeds £150,000 in the tax year
- Someone who received child benefit and has an adjusted net income above the High-Income Child Benefit threshold
If you are unsure whether you need to complete a Self-Assessment return, HMRC has an online checker tool. Alternatively, speak to your accountant.
What Is the Self-Assessment Deadline?
There are two main Self-Assessment deadlines to be aware of:
- 31 October: the deadline for paper tax returns for the tax year ending the previous 5 April.
- 31 January: the deadline for online tax returns and for payment of any tax owed. This is also the deadline for the first payment on account for the following tax year, if applicable.
The vast majority of people file online, making the 31 January deadline the one that matters most. Missing this deadline results in an immediate £100 penalty, with further penalties accruing for continued delays. Filing early is always the better approach.
What Expenses Can You Claim as a Sole Trader?
One of the most important aspects of completing your Self-Assessment return correctly as a sole trader is ensuring you claim all allowable business expenses. These reduce your taxable profit and therefore your tax liability. Allowable expenses include:
- Office costs such as stationery, phone bills and postage
- Travel costs including business mileage, train fares and parking
- Clothing costs for uniforms or protective clothing that are required for work
- Staff costs including wages, salaries and subcontractor costs
- Financial costs including bank charges, professional indemnity insurance and accountancy fees
- Costs of goods purchased for resale
- Use of home as office, if you work from home
Expenses must be wholly and exclusively for business purposes to be deductible. Personal costs or mixed-use items require careful treatment.
How to Complete Your Self-Assessment Tax Return Step by Step
- Register for Self-Assessment. If this is your first time, you must register with HMRC by 5 October following the end of the tax year in which you became liable.
- Gather your records. Collect all relevant documents including income records, bank statements, expense receipts, P60s or P45s from employment, dividend vouchers and any other income documentation.
- Log in to HMRC online. Access your Self-Assessment account through the Government Gateway using your Unique Taxpayer Reference (UTR) number.
- Complete the relevant sections. Fill in all applicable sections of the return, including income from self-employment, employment, property, dividends and any other sources.
- Claim your allowable expenses and reliefs. Enter all deductible business expenses and any tax reliefs you are entitled to claim.
- Review your return. Check all figures carefully before submitting. HMRC will calculate your tax liability based on the information you provide.
- Submit and pay. Submit your return and pay any tax owed by 31 January.
How Affinity Associates Isaacs & Co Can Help
At Affinity Associates Isaacs & Co, we prepare and file Self-Assessment tax returns for sole traders, limited company directors, landlords and individuals with complex tax affairs across Greater Manchester and beyond. We review your income and expenses carefully to ensure you claim everything you are entitled to, minimise your tax liability and file well ahead of the deadline. If your Self-Assessment feels overwhelming, let us take it off your hands.
Leave your Self-Assessment to us
Affinity Associates Isaacs & Co prepares and files Self-Assessment returns for sole traders, directors and landlords across Greater Manchester, making sure you claim everything you are entitled to and never miss a deadline. Book your free consultation today to get started.