So, Can I Claim Expenses on My Self Assessment?
If you are self-employed, one of the most common questions you might have when completing your tax return is: Can I claim expenses on my Self Assessment? The simple answer is yes — but only certain costs qualify. Understanding which expenses are allowed can reduce your tax bill and help you stay compliant with HMRC rules.
This guide explains what counts as an allowable expense, what you cannot claim, and how to record your spending correctly.
What Are Allowable Expenses?
Allowable expenses are the everyday running costs of your business. They are costs you pay to keep your business operating and earning income. By claiming them, you reduce your taxable profit, meaning you pay less tax.
HMRC only allows expenses that are wholly and exclusively for business use. This means you cannot claim for anything that also has a personal benefit. Full details can be found in the HMRC manuals.
Examples of Allowable Business Expenses
Here are some of the main types of costs you can claim on your Self Assessment:
- Office costs – such as stationery, postage, and printing.
- Travel expenses – including fuel, parking, train tickets, and mileage.
- Marketing and advertising – website costs, flyers, and online ads.
- Professional fees – such as accounting services and legal advice.
- Insurance – public liability or business equipment insurance.
- Rent and utilities – if you rent an office or workspace.
- Phone and internet – when used for business purposes.
- Bank charges – fees on business accounts and credit cards.
- Training costs – courses that maintain or improve existing skills.
If you work from home, you may also claim a proportion of your household bills.
What You Cannot Claim
Some expenses cannot be claimed because they are not considered essential to the business or have a personal element. These include:
- Personal clothing (unless it’s protective or branded workwear)
- Entertaining clients
- Fines or penalties
- Personal expenses, such as food and drink not related to business travel
If an item is used for both business and personal reasons — for example, a mobile phone — you can only claim the business portion.
Claiming for Working from Home
If you work from home, HMRC allows you to claim part of your household expenses. This includes heating, electricity, rent, and broadband. You can calculate this either by using HMRC’s flat rate or by working out the actual business proportion of each bill.
Many business owners use professional bookkeeping services to ensure these calculations are accurate.
Claiming for a Vehicle
You can claim expenses for using your vehicle for business purposes. This can be done in two ways:
- Flat rate (simplified expenses) – using HMRC’s mileage rates.
- Actual costs – claiming a proportion of fuel, insurance, repairs, and servicing.
If you use the vehicle for personal trips as well, you must separate business and private mileage.
How to Record Expenses
Keeping accurate records is essential. HMRC requires evidence for all claims, which may include receipts, invoices, or bank statements. Records should be stored for at least five years after the Self Assessment deadline.
Digital accounting tools and professional support help keep these records organised. Using approved software is also important under Making Tax Digital (MTD) rules.
How to Include Expenses on Your Tax Return
When completing your Self Assessment, you report total income and then deduct allowable expenses. HMRC calculates tax based on your net profit (income minus expenses).
If your records are incomplete, do not guess. Incorrect figures can lead to penalties or investigations. Professional support ensures your return is both accurate and compliant.
At TRW Accountants, we provide expert assistance with tax returns for self-employed individuals and small businesses, ensuring all eligible expenses are claimed correctly.
Why Claiming Expenses Properly Matters
Claiming expenses accurately not only lowers your tax bill but also protects you during HMRC reviews. Submitting incorrect or incomplete information can result in fines or additional tax charges.
By keeping detailed records, filing on time, and seeking advice early, you make the process far easier each year.
Common Mistakes to Avoid
When it comes to Can I claim expenses on my Self Assessment?, there are a few common errors to watch for:
- Mixing personal and business expenses.
- Forgetting smaller deductions, like subscriptions or parking fees.
- Claiming full costs instead of a business proportion.
- Losing receipts or digital records.
Avoiding these mistakes keeps your return compliant and reduces the chance of penalties.
Local Support in Kent
If you run a small business or work as a sole trader in Dover or the wider Kent area, professional help makes managing expenses easier. Comparing local accountants helps you find support tailored to your needs.
At TRW Accountants, we provide ongoing advice, accurate record-keeping, and clear explanations to help clients across Kent manage their finances effectively.
Final Thoughts
So, can you claim expenses on your Self Assessment? Yes — but only if they are legitimate business costs. Understanding the difference between what you can and cannot claim makes a real difference to your final tax bill.
If you want to ensure your claims are accurate and compliant, you can contact us at TRW Accountants. We’ll help you manage your records, file on time, and make the most of your allowable expenses.