The 45p mileage allowance: a plain-English guide for the self-employed

Published July 2026 · 7 min read

If you drive for work, mileage is probably one of your biggest allowable expenses — and one of the easiest to under-claim, because it only exists if you record it. HMRC’s simplified expenses route gives self-employed drivers a flat rate per business mile instead of tracking every fuel receipt and repair bill.

The rates for 2026/27

• 45p per mile for the first 10,000 business miles in the tax year (6 April to 5 April). This rate has held steady for years — it isn’t linked to fuel prices, so it’s always worth checking the current figure rather than assuming.
• 25p per mile for every business mile above 10,000.

Ten thousand miles at 45p is a £4,500 deduction from taxable profit — worth roughly £1,170 to a basic-rate taxpayer once Class 4 NI is counted. That’s not small change for scribbling down trips.

What the flat rate covers

Everything about running the vehicle: fuel, insurance, servicing, repairs, MOT, depreciation. That’s the deal — one simple number instead of a folder of vehicle bills.

Which miles count?

• Yes: travel between jobs and changing sites, trips to the merchant, quoting visits, trips to your accountant.
• No: ordinary commuting to a single regular workplace, and personal trips.

For most subbies moving from site to site, the bulk of work driving qualifies. If you work from one fixed yard every day, that home-to-yard run is commuting.

Mileage vs actual costs — which wins?

Rough guide: high annual business mileage in a cheap-to-run vehicle favours the flat rate; low mileage in an expensive, thirsty van can favour actual costs. Do the comparison once with your accountant, then commit. For many sole-trader subbies, 45p with zero paperwork beats a slightly bigger claim that requires every receipt filed.

How to log miles without hating your life

HMRC expects a record: date, journey, business purpose, miles. A notebook works until it doesn’t. On SubReady you just message it on WhatsApp as it happens:

• “34 miles to the Leeds job and back”
• “Did 120 miles today between sites”

SubReady logs the trip, applies 45p/25p automatically across the 10,000-mile threshold, and asks “how many miles this year?” gets you a live answer. The year’s mileage allowance flows into your tax estimate and Annual Return with no year-end maths. Step-by-step: logging mileage.

Quick worked example

A plasterer drives 13,000 business miles in 2026/27:

• First 10,000 miles × 45p = £4,500
• Next 3,000 miles × 25p = £750
• Total deduction: £5,250 off taxable profit — recorded one WhatsApp message at a time.

Illustrative figures; your position depends on your circumstances — check anything marginal with your accountant.

Mileage questions we hear on site

Can I claim mileage on a van the business paid for?

The flat rate is designed for vehicles you own personally and use for work. If you’ve been claiming the van’s actual costs (purchase, fuel, repairs) you’re on the actual-cost method for that vehicle and can’t switch to mileage while you keep it. One vehicle, one method — pick it once, with your accountant if unsure.

Do passenger or tool-carrying miles change anything?

For the self-employed the rate is per business mile, full stop — there’s no extra for carrying materials or a labourer. (Passenger supplements exist for employees, a different scheme.)

What happens at the 10,000-mile line?

The threshold resets every tax year on 6 April. Cross it mid-year and only the miles above 10,000 drop to 25p — SubReady applies the split automatically, so a 13,000-mile year is simply 10,000 × 45p + 3,000 × 25p without you doing anything.

What if I forget to log for a fortnight?

Reconstruct honestly — diary, job sheets, sat-nav history — and log it in one message (“did about 260 miles over the last two weeks between the Harrogate and York jobs”). Then get back to the habit; contemporaneous records always stand up better.

Start capturing every mile

The allowance only pays if the miles are written down. Put the logbook where you already are — WhatsApp — and it actually happens. SubReady is £8.99/month after a 14-day free trial, and mileage is one message: sign up, drive, text the miles.