Being your own boss as a sole trader comes with plenty of freedom, but it also means taking full responsibility for your own tax affairs. One of the simplest ways to reduce how much Income Tax and National Insurance you pay each year is to claim every allowable business expense you’re entitled to yet many self-employed people in the UK still underclaim, either through uncertainty or a fear of getting it wrong.

In this guide, we will explain exactly what counts as an allowable business expense for sole traders in the 2026/27 tax year, how HMRC’s ‘wholly and exclusively’ rule works in practice, and where the trading allowance might suit you better than itemising costs. By the end, you will have a clear picture of how to keep more of your hard-earned profit, while staying fully compliant with HMRC.

What Counts as an Allowable Business Expense?

When you are self-employed, you pay Income Tax on your trading profits rather than on your total turnover. This means you can reduce your taxable profit by claiming allowable business expenses.

Key points to understand:

• Allowable business expenses are the legitimate costs of running your business.
• These expenses are deducted from your business income before your tax liability is calculated.
• The more allowable expenses you accurately record, the lower your taxable profit, which can reduce the amount of tax you owe.
• According to HMRC, an expense must be incurred "wholly and exclusively" for business purposes to be tax-deductible.
• If an expense has both business and personal use (such as a mobile phone), you can generally claim only the business proportion, provided you can demonstrate how the business use was calculated.
• You should keep accurate records and receipts for every expense you claim.
• HMRC requires sole traders to retain these records for at least five years after the 31 January submission deadline for the relevant tax year.
• All allowable business expenses must be reported as part of your annual self-assessment tax return.

The Trading Allowance: An Alternative To Claiming Expenses

If your self-employed income is relatively modest, or your expenses are minimal, you might prefer to use the trading allowance instead of itemising every cost. For the 2026/27 tax year, the trading allowance remains at £1,000, allowing you to deduct this flat amount from your gross trading income instead of claiming individual expenses.

If your total trading income is £1,000 or less in the tax year, this is covered automatically and you generally won’t need to register for self-assessment or pay tax on it. Where your income exceeds £1,000, you can choose between deducting the £1,000 trading allowance or deducting your actual allowable expenses but not both. As a rule of thumb, if your genuine business costs are higher than £1,000, claiming your actual expenses will usually reduce your tax bill by more.

Allowable Expenses You Can Claim as a Sole Trader

Office Costs, Equipment and Technology

Stationery, postage, printing, computer software and consumables used for your business are fully deductible. Laptops, phones, printers and other equipment can also be claimed, either as a direct expense or through capital allowances, provided they’re for business use.

Travel and Business Mileage

Travel that’s wholly and exclusively for business purposes is an allowable expense, including train and bus fares, parking, tolls and congestion charges. Regular commuting to a single, permanent place of work doesn’t qualify. If you use your own car, van or motorbike for business journeys, you can either claim the actual running costs (proportioned for business use) or apply HMRC’s simplified mileage rates, which currently allow 45p per mile for the first 10,000 business miles in a tax year for cars and vans, dropping to 25p per mile thereafter, and 24p per mile for motorbikes.

Use of Home as Office

If you work from home, you can claim a proportion of your household running costs including heating, electricity, council tax, rent or mortgage interest, and internet based on the rooms used and the time spent working there. Alternatively, HMRC’s simplified flat-rate scheme lets you claim a fixed monthly amount based on the number of hours you work from home, without needing to calculate exact proportions.

Staff and Subcontractor Costs

If your business employs staff or uses subcontractors, you can claim salaries, employer’s National Insurance contributions, pension contributions, agency fees and relevant training costs. As a sole trader, your own ‘wages’ or profit drawn from the business are not an allowable expense, as you and the business are treated as one legal entity for tax purposes.

Business Premises and Utilities

Where you rent a shop, studio, workshop or office, you can claim rent, business rates, utility bills, property insurance and security costs. The purchase of business premises itself isn’t an allowable expense for sole traders, though certain repair and maintenance costs can be claimed.

Stock, Materials and Goods for Resale

The cost of raw materials, stock purchased for resale, and goods or services bought in to fulfil client work are all allowable, provided they relate directly to your trade.

Insurance, Legal and Professional Fees

Premiums for public liability insurance, professional indemnity insurance and business contents insurance are deductible. Legal fees, accountancy fees and other professional costs directly related to running your business are also allowable, provided they aren’t connected with buying capital assets or settling personal matters.

Marketing, Advertising and Subscriptions

Costs for advertising, website design and hosting, business cards, directory listings and SEO or PR services are all allowable. Membership of HMRC-recognised professional bodies and trade subscriptions relevant to your work can also be claimed, provided they’re necessary for your trade rather than a personal interest.

Training and Professional Development

You can claim the cost of courses that maintain or update skills and knowledge you already use in your trade. However, training that equips you with an entirely new skill set to move into a different trade or profession generally won’t qualify, as HMRC views this as a capital cost rather than a revenue expense.

Bank Charges and Finance Costs

Interest on business loans, overdraft charges, credit card fees and leasing or hire purchase interest relating to your business bank accounts and finance arrangements are allowable. Repayments of the loan capital itself, and any charges on personal accounts, are not.

Clothing and Uniforms

Everyday clothing, including office dress, can never be claimed, even if you only wear it for work, because it has an inherent dual purpose. Genuine uniforms bearing a business logo, and protective clothing such as steel-toe boots or hi-vis gear, are fully allowable.

Expenses you cannot Claim as a Sole Trader

A handful of common costs are specifically disallowed by HMRC, no matter how they’re framed:

•        Fines and penalties, such as parking tickets, even if incurred while driving for business

•        Client and supplier entertaining, including meals, drinks and hospitality

•        Personal expenses with no clear business purpose

•        Everyday clothing, regardless of whether it’s worn exclusively for work

•        Childcare costs, although tax-free childcare support is available separately

•        Pension contributions, which instead qualify for personal tax relief rather than being treated as a business expense

Quick-reference Table: Sole Trader Allowable Expenses

How to Keep Accurate Records of your Expenses

Whichever expenses you claim, accurate record-keeping is essential. Keep every receipt and invoice, log mileage as you travel, and reconcile your figures regularly rather than leaving everything until January. With Making Tax Digital for Income Tax now extending to more sole traders and landlords from April 2026, maintaining digital records throughout the year rather than relying on a shoebox of paper receipts will increasingly become the norm rather than a nice-to-have.

Cloud accounting software, or a well-maintained spreadsheet, can make this process far less stressful, giving you an accurate, up-to-date picture of your taxable profit at any point in the year, rather than a last-minute scramble before the self-assessment deadline.

How Consultax Can Help

Working out exactly which costs you can and can’t claim isn’t always straightforward, and getting it wrong in either direction can prove costly.

At Consultax Chartered Accountants, our professional team, led by partner Varun Gupta ACA, works closely with sole traders and small business owners across the UK to identify every allowable expense, structure their record-keeping correctly, and ensure their self-assessment return is accurate and submitted on time. With experience spanning roles at firms including PwC, UBS and BNP Paribas, our chartered accountants combine technical precision with practical, jargon-free advice, helping you stay compliant while keeping more of what you earn.

Conclusion

Claiming the right business expenses is one of the most effective ways for a sole trader to reduce their tax bill legitimately. From office costs and travel to use of home and professional subscriptions, understanding what HMRC will and won’t accept and keeping the records to back up your claims puts you firmly in control of your finances. Whether you choose to itemise your expenses or rely on the trading allowance, the key is consistency, accuracy and, where needed, professional guidance to make sure you’re neither overpaying tax nor leaving yourself exposed to an HMRC enquiry.