The short answer
Allowable expenses are business costs that are properly incurred for the trade and supported by records. The detail differs for sole traders and limited companies, and some costs need careful treatment because there is private use, capital spending or employee/director benefit rules involved.
Useful expense categories to organise
- Software, subscriptions, phone and internet costs used for the business.
- Travel, mileage, parking and business journeys, separated from commuting/private use.
- Tools, equipment, laptops and office items, with capital purchases clearly flagged.
- Marketing, website, professional fees and insurance.
- Training linked to the current business, not a completely new trade.
What good records look like
Good expense records show what was bought, when, why it relates to the business, how it was paid, and whether any private-use adjustment is needed. A photo of a receipt can help, but the explanation behind unusual costs matters too.
For growing businesses, the aim is to create a repeatable monthly routine instead of rebuilding the year from bank statements near the deadline.
Red flags to check before claiming
Entertainment, clothing, home office costs, mixed-use vehicles and one-off equipment purchases often need more judgement than a simple receipt upload. Treat online lists as prompts, not personal advice.