HMRC Self-Assessment Expense Grader
Work out your total allowable expenses for Self Assessment and see how much they could reduce your tax bill.
Business mileage
45p/mile for the first 10,000 miles, 25p/mile after that (HMRC Approved Mileage Allowance).
Working from home
Mobile phone bill
Software, subscriptions & other costs
Estimate your tax saving (optional)
Allowable Expenses Total
£5,926.00
Figures are based on HMRC's simplified expenses flat rates and standard Income Tax and Class 4 National Insurance rates for 2026/27. This tool is a guide only — always keep proper records and check specific expense rules with HMRC or an accountant before submitting your Self Assessment return.
About HMRC's simplified expenses
HMRC allows self-employed people to use simplified flat rates for certain expenses instead of working out the exact business proportion of costs. For mileage, this means 45p per mile for the first 10,000 business miles in a year, then 25p per mile after that, regardless of your vehicle's actual running costs. For working from home, you can claim a flat £6 per week with no receipts needed, or calculate the actual proportion of your household bills based on the rooms and time used for business.
Other costs — like software subscriptions, a business-use proportion of your mobile phone bill, and general running costs — are claimed at their actual cost, provided they're wholly and exclusively for business purposes (or fairly apportioned where there's mixed personal and business use). Keep records to support any expense you claim, in case HMRC asks for evidence.
Not yet registered for Self Assessment? Check the 5 October registration deadline to make sure you don't miss it.