An expense is not automatically allowable because it was paid from a business account. For a sole trader, HMRC’s general rule is that costs must be allowable for the business, with personal elements excluded or apportioned where the rules permit.
This guide is written for Scottish trade readers. Check the current position against HMRC allowable-expense guidance, HMRC simplified expenses and HMRC capital allowances; project and business circumstances can change the answer.
Use categories as prompts, not guarantees
Tools, materials, insurance, accountancy, phone use, travel and premises costs may be relevant, but the treatment depends on facts and accounting method. Check the current HMRC category guidance. For related practical context, see trade casement windows.
Handle mixed use carefully
Where a vehicle, phone or premises has both business and private use, retain the basis for any apportionment. Avoid claiming an unsupported round percentage. The existing guide to pricing window fitting work helps connect the decision to job costing.
Distinguish routine costs from assets
Longer-life equipment may fall under capital-allowance rules rather than being treated like consumable materials. Finance arrangements can also change the treatment. It is also worth reviewing setting up a window trade account before committing to recurring supply.
Keep evidence alongside the decision
Retain receipts and invoices, note the business purpose and ask an adviser about unusual costs before the return deadline.
Working checklist
| Cost area | Evidence to retain | Question to resolve |
|---|---|---|
| Tools and consumables | Supplier invoice and job use | Expense or capital item? |
| Vehicle and travel | Mileage or cost records | Business/private split? |
| Phone and software | Bills and subscription terms | Business proportion? |
| Clothing and PPE | Itemised receipt | Protective or ordinary clothing? |
Next step
Confirm the project facts in writing before relying on a general guide. Trade Windows Scotland supplies made-to-measure windows to trade customers; the related Clyde Windows uPVC window service provides additional affiliated service context.
This article provides general business information, not tax, accounting or legal advice. Check current official guidance and obtain advice for your circumstances.
Apply the business-purpose test to the facts
For a sole trader, an expense normally needs to be incurred wholly and exclusively for the trade. Some mixed costs can be apportioned where the business element is identifiable, but a personal cost does not become deductible because it was paid from the business bank account. Start with what was bought, why it was needed and how any private use was excluded or measured.
Keep the invoice, proof of payment and a short note where the purpose is not obvious. A hardware-store receipt saying only ‘goods’ is weak evidence; add the job reference and item detail. Consistency matters, but last year’s treatment is not proof that it was correct. Check current HMRC guidance when an item is unusual or significant.
Separate direct job costs from overhead
Frames, sealed units, ironmongery, trims, sealants, fixings, skips, access equipment and project-specific subcontract labour are usually direct costs of a job. Insurance, bookkeeping, software, advertising, workshop costs and general small tools are overheads. Recording the distinction does not decide tax treatment, but it reveals whether the price recovered the work’s true cost.
Post credits and refunds back to the same job and category. If material is bought in bulk, use a reasonable method to allocate usage. Do not ignore waste, redelivery, parking or return visits: they can be valid business costs and important margin information even when their tax category differs.
- Attach a readable receipt or invoice.
- Record the business reason and job reference.
- Separate VAT correctly if registered.
- Document any business/private apportionment.
Handle vans, travel, home working and clothing carefully
Vehicle claims may use actual allowable costs with a supported business-use split or simplified mileage where the rules permit. Keep a mileage log showing date, route, purpose and distance; commuting and private journeys need separate consideration. Once a method is chosen for a vehicle, restrictions can apply to changing it, so compare the options before adopting one.
Home-working claims need a reasonable basis or the applicable simplified-expense method. Ordinary clothing is generally private even if it is worn only for work, while protective clothing or a genuine uniform can be different. Meals and subsistence have specific limits and are not automatically allowable because the day was long. Use HMRC’s category guidance rather than relying on trade folklore.
Distinguish equipment from day-to-day expense
A low-cost consumable and a long-life saw, van or workshop machine may require different accounting treatment. Depending on the accounting basis, capital allowances or the cash-basis rules can affect when relief is obtained. Finance payments also need splitting between the asset, interest and charges. Ask an accountant before year end when planning a large purchase instead of assuming the entire payment reduces taxable profit immediately.
Tax relief should not be the sole reason to spend. Check that the purchase improves safety, capacity or margin, compare its cash timing with upcoming tax and supplier commitments, and retain finance agreements and disposal evidence. A clean fixed-asset list also helps with insurance and replacement planning.