Understanding allowable expenses is critical for reducing clients’ Self Assessment tax bills. This article from Sage covers the essentials: what counts as an allowable expense, how to claim, and why accurate record-keeping matters under HMRC rules.

From office equipment and professional fees to travel, marketing and working-from-home costs, the guide outlines common claims and highlights areas where clients often miss out. It also explains simplified expenses for vehicles and home working, plus the importance of distinguishing between capital and revenue costs.

With Making Tax Digital for Income Tax coming in April 2026, accountants should help clients transition to digital record-keeping now – paper receipts won’t cut it.

The article also addresses practical issues such as tracking expenses, handling HMRC audits, and managing claims for multiple businesses or side hustles. It’s packed with tips to ensure clients claim correctly and avoid penalties, while maximising tax relief.

Read Sage's article on allowable expenses you can claim if you're self-employed