Allowable expenses reduce the profit you pay tax on. Most sole trader tradespeople claim the obvious ones (materials, the van) and leave the rest on the table because the receipts never made it home. This is the list, then the habit.
What is usually allowable for a trade business
- Materials and consumables bought for jobs, and tools you use in the work.
- The van: fuel, insurance, repairs and servicing, or simplified mileage if you use the flat rate instead. One method per vehicle.
- Public liability and other business insurance.
- Trade certifications, registrations and the training that keeps them current.
- A share of your phone and internet, in proportion to business use.
- Protective clothing and workwear with the business name on it (ordinary clothes are not allowable).
- Accountancy, software and bank charges for the business account.
- Working from home: a proportion of costs, or HMRC's flat rate.
The rule behind every line is the same: wholly and exclusively for the business. Anything mixed is claimed in proportion, and the proportion needs a reason you could explain.
What HMRC expects behind the numbers
Records that show what was bought, when, from whom, and for how much, kept for at least five years after the 31 January filing deadline for that tax year. From April 2026, in stages by income, those records must be digital under Making Tax Digital for Income Tax, and the quarterly updates are drawn from them.
The habit
Photograph the receipt at the counter and attach it to the expense line the same day. That is the whole habit. An expense with its receipt attached is a claim; an expense you remember with a receipt somewhere in the van is a hope.
Tradelynx Books is built around that habit: Tradelynx jobs land as income lines automatically, expenses are added with their receipt attached, and VAT is worked out as you go. It is MTD-ready and does not file to HMRC yet (you file from the export until Tradelynx is recognised), it works from any GB postcode, and the honest list of what it does and does not do is at tradelynx.co.uk/books.
Check your own position against GOV.UK's guidance on expenses if you are self-employed; the categories above are the common ones, not a ruling on yours.