Allowable expenses for the self-employed

The rule sounds simple: expenses are allowable if they're incurred wholly and exclusively for the business. In practice the money is in knowing how that rule applies to the grey areas — and most self-employed people leave real money unclaimed every year out of caution or simply not knowing.

The straightforward claims

• Materials, stock and direct costs of what you sell
• Tools and equipment (via the annual investment allowance for bigger items)
• Phone and internet — the business proportion
• Software, subscriptions and professional fees (including your accountant)
• Insurance, bank charges on the business account, advertising and marketing
• Staff and subcontractor costs
• Travel to temporary work locations, and either actual vehicle costs or 45p/mile (25p after 10,000 miles)

The ones people miss

Use of home: either HMRC's flat rate (£10–£26/month depending on hours) or a calculated share of rent or mortgage interest, council tax, utilities and insurance based on rooms and business hours. Full-time home workers almost always claim more with the calculated method.

Pre-trading expenses: costs incurred up to seven years before you started trading — equipment you already owned, courses, setup costs — can often be claimed on day one.

Training that updates existing skills is allowable (a course keeping you current in your field); training that gives you a brand-new skill traditionally isn't, though the rules have softened for keeping-pace digital skills.

The traps

Client entertaining is not deductible — coffee with a client comes out of your own pocket, tax-wise. Ordinary clothing isn't claimable even if you only wear it for work (protective gear and genuine uniforms are). And the 'wholly and exclusively' test kills dual-purpose claims: a family holiday with one client meeting attached doesn't become a business trip.

The repairs-versus-improvements line matters for anyone with premises: fixing is deductible now, upgrading is capital. Getting it wrong in your favour is the kind of pattern that invites an HMRC look.

Keep the evidence

Claims survive scrutiny when receipts, invoices and a sensible method sit behind them. Digital records (photograph receipts as they happen) beat the January shoebox in every way — and if the shoebox is where you are, that's fine too: our sole trader accounts service exists precisely to turn it into a defensible return with everything claimed.