7 Self-Employed Expenses You're Probably Forgetting to Claim

The self-employed expenses most often forgotten are use of home, business mileage, phone and broadband, professional subscriptions, bank and finance charges, training that maintains existing skills, and a proportion of equipment used partly for work. Each of these is a legitimate deduction that reduces your taxable profit, yet sole traders routinely leave them off their tax return and pay more tax than they need to. Understanding allowable expenses self-employed UK 2026 rules allow is one of the simplest ways to keep more of what you earn. Blue Tick Accountants, a Guildford-based UK tax advisory and accountancy practice, helps sole traders claim everything HMRC permits while staying fully compliant. This article walks through seven commonly missed expenses and shows what they can be worth.

Key Takeaways

• An expense is allowable for the self-employed only if it is incurred wholly and exclusively for business purposes, the core test HMRC applies to every deduction.
• Use of home can be claimed using HMRC's simplified flat rate, from £10 to £26 a month depending on hours worked, or by apportioning actual household costs.
• Business mileage can be claimed at 55p per mile for the first 10,000 miles in a year and 25p per mile thereafter using HMRC's simplified rates.
• Training that maintains or updates skills you already use in your trade is allowable, while training to acquire a brand-new skill or trade is not.
• From 6 April 2026, sole traders with qualifying income above £50,000 must keep digital records and file quarterly updates under Making Tax Digital for Income Tax, making accurate expense records more important than ever.

What counts as an allowable expense for the self-employed?

An allowable expense is any cost incurred wholly and exclusively for your business, which you deduct from turnover to arrive at the taxable profit HMRC assesses. If a cost has both a business and a private element, only the business proportion is allowable, and you must be able to justify how you split it.

This wholly and exclusively rule is the single test behind every sole trader expenses HMRC will accept. Everyday costs such as stock, materials, and advertising are rarely missed. The expenses that slip through tend to be part-business, part-personal costs, such as your home, car, or phone, where people either forget the business share exists or assume it is too small to bother with. Over a year, those small shares add up, which is exactly why knowing what can self-employed claim matters.

Which 7 expenses do sole traders most often miss?

The seven expenses sole traders most commonly forget to claim are set out below, each of which is allowable where a genuine business purpose exists.

1. Use of home as an office. Claim HMRC's flat rate of £10 to £26 a month based on hours worked, or a fair share of actual heating, lighting, and broadband costs.
2. Business mileage. Claim 55p per mile for the first 10,000 business miles and 25p thereafter, or a proportion of actual running costs if you prefer.
3. Mobile phone and broadband. Claim the business percentage of contracts used for work calls, emails, and online services.
4. Professional subscriptions and memberships. Claim fees for HMRC-approved professional bodies and trade associations relevant to your work.
5. Bank, card, and finance charges. Claim interest and charges on business accounts, business loans, and card processing fees.
6. Training to maintain existing skills. Claim courses that update or refresh skills you already use in your trade.
7. Equipment used partly for business. Claim the business proportion of laptops, tools, and cameras through capital allowances or the trading allowance where relevant.

For a complete list and the rules behind each category, see our guide to allowable expenses for the self-employed.

How much can these expenses save you? A worked example

Claiming commonly forgotten expenses can reduce a sole trader's tax bill by several hundred pounds a year. Consider a self-employed designer, a basic-rate taxpayer, with £45,000 of turnover who previously claimed only obvious costs.

In 2026/27 she adds the following: use of home at £26 a month (£312), business mileage of 4,000 miles at 55p (£2,200), 70% of a £600 annual phone and broadband bill (£420), a professional subscription (£180), and a skills-refresher course (£500). Together these add £3,612 of allowable expenses she had been missing. As a basic-rate taxpayer paying 20% income tax plus 6% Class 4 National Insurance, that reduces her tax and National Insurance by roughly £939. The same expenses claimed by a higher-rate taxpayer would save more, because relief is given at their marginal rate.

How does Making Tax Digital change record-keeping?

Making Tax Digital for Income Tax (MTD for IT) changes how the self-employed record and report expenses, and it is now live. From 6 April 2026, sole traders and landlords with qualifying income above £50,000 must keep digital records and submit quarterly updates to HMRC, followed by a final declaration by 31 January.

Those with qualifying income above £30,000 join from April 2027, and those above £20,000 from April 2028, so most sole traders will be inside the regime within a few years. The practical point is that expenses can no longer be reconstructed from a shoebox of receipts at the last minute. Using compatible software to log costs as they arise means the forgotten expenses in this article are captured automatically, which both lowers your tax and keeps you compliant. If your income is below the current threshold you continue with self-assessment for now, but adopting digital records early makes the eventual switch painless.

Frequently Asked Questions

What expenses can I claim as self-employed in the UK?

As a sole trader you can claim any cost incurred wholly and exclusively for your business, including stock, office costs, travel, use of home, phone and broadband, professional subscriptions, insurance, bank charges, and training that maintains existing skills. Costs with a private element are apportioned, and only the business share is allowable against your taxable profit.

Can I claim working from home as self-employed?

Yes, you can claim use of home as a self-employed person. HMRC offers a simplified flat rate of £10 to £26 a month depending on the hours you work from home, which requires no calculations. Alternatively you can apportion actual costs such as heating, electricity, and broadband based on the rooms and time used for business.

Is training an allowable expense for the self-employed?

Training is allowable if it maintains, updates, or refreshes skills you already use in your existing trade. Training to acquire an entirely new skill or to start a different trade is treated as capital and is not deductible. For example, a plumber's refresher course is allowable, but a course to retrain as an electrician usually is not.

How do I claim business mileage as a sole trader?

You can claim business mileage using HMRC's simplified rates of 55p per mile for the first 10,000 business miles in a tax year and 25p per mile after that. Alternatively you can claim the business proportion of actual vehicle running costs. You must keep a record of business journeys, including dates, destinations, and mileage.

Do I need to keep digital records for expenses now?

If your qualifying income as a sole trader or landlord is above £50,000, you must keep digital records and file quarterly updates under Making Tax Digital for Income Tax from 6 April 2026. Those above £30,000 join from April 2027 and those above £20,000 from April 2028. Below these thresholds, self-assessment continues for now.

How Blue Tick Can Help

Blue Tick Accountants reviews your self-employed accounts to make sure every allowable expense is claimed, from use of home to mileage and training, so you never pay more tax than you owe. As a Guildford-based practice supporting sole traders across the UK, Blue Tick Accountants also gets you set up for Making Tax Digital so your records stay compliant and complete. Head to our website and book a meeting now.

Conclusion

The expenses sole traders forget are rarely the obvious ones, they are the part-business costs such as your home, car, phone, and training that quietly add up across a year. Claiming them correctly can save hundreds of pounds while keeping you fully within HMRC's rules. Keep digital records as costs arise, apply the wholly and exclusively test honestly, and review your expenses before you file so nothing legitimate is left behind.

About the Author

This guide was written by Leon, founder of Blue Tick Accountants, a Guildford-based UK tax advisory and accountancy practice that helps the self-employed, landlords and limited company owners across the UK. It was last reviewed for the 2026/27 tax year.

This article is intended for general informational purposes only and does not constitute tax, legal, or financial advice. Tax rules are subject to change and their application will depend on your individual circumstances. You should always seek advice from a qualified professional before taking action. Blue Tick Accountants accepts no liability for decisions made on the basis of this content.