MOD Tax Refund Calculator for Service Mileage

The MOD tax refund calculator estimates what business miles in your own car could be worth in tax. Relief is HMRC’s approved rate for each mile minus any mileage the MOD paid, and your tax rate sets how much comes back. It does not take off MOD payments, so that step is yours.

The car rate for the first 10,000 business miles went from 45p to 55p on 6 April 2026, and that’s the change older figures miss. Years before that stay at 45p, so a claim that reaches back isn’t priced at one rate.

Whether you’re Army, Navy or RAF, the figures below fit the armed forces mileage claim you’d make for driving your own vehicle to a temporary workplace or on duty.

What moves the answer is the tax year each journey falls in, the MOD’s payments towards those miles, and your tax rate. Have all three to hand before you run the MOD tax refund calculator, or the estimate won’t mean much.

What the MOD tax refund calculator adds up

The MOD tax refund calculator asks for two things: the business miles you drove in a tax year and the rate of tax you pay. Behind the result sits a simple sum, where miles at the approved rate give a relief figure and your tax rate turns that into money.

Business miles means journeys in your own vehicle to a temporary workplace or while on duty. Driving from home to a permanent workplace counts as ordinary commuting, which earns no relief.

The line is 40% or more of your working time at one place, over a period that has run or is expected to run past 24 months. Cross it and the posting becomes a permanent workplace, and the MOD tax rebate guide explains how that expectation is judged.

Count every business mile, including duty journeys the MOD paid for. Its payments come off at the end, not by leaving miles out.

Run the calculator once for each tax year. Every year has its own first 10,000 miles, and the rate for those miles depends on the year.

Relief and refund aren’t the same number. £1,000 of relief is worth £200 to someone paying 20% and £400 at 40%.

Relief for a year that’s still running usually arrives through your tax code. A past year’s relief can come as a code change or as a repayment from HMRC.

AMAP mileage rates rose to 55p in 2026

AMAP stands for approved mileage allowance payments, and AMAP mileage rates set a pence-per-mile figure for business trips in a vehicle you own. One rate stands in for every running cost, which is why a fuel receipt or a garage bill adds nothing to the claim.

The rates that apply depend on the tax year:

• In 2026/27, cars and vans get 55p for each of the first 10,000 business miles, then 25p for every mile beyond.
• From 2011/12 to 2025/26, that same band was priced at 45p, with 25p beyond it.
• Motorcycles get 24p and bicycles 20p a mile in both periods, with no change after 10,000 miles.

That answers the 45p question too. The 45p per mile tax relief covers the first 10,000 business miles of each tax year up to 2025/26, and any further miles in the same year drop to 25p.

The claim window runs across both rates. A claim can take in the tax year you’re in and the four before it, so during 2026/27 that means four years at 45p (2022/23 to 2025/26) plus the current year at 55p. The deadline for 2022/23 is 5 April 2027.

The rate table on GOV.UK shows both periods side by side, and the approved mileage rates FAQ adds the passenger rate.

MOD payments reduce an armed forces mileage claim

An armed forces mileage claim is built on the shortfall: the approved amount less whatever the MOD put towards the same miles. The calculator leaves that gap open, so close it by hand.

The MOD payments to take off include Motor Mileage Allowance (MMA) for journeys on duty, Home to Duty Travel (HDT) and Get You Home Travel (GYH(T)). The Low Incomes Tax Reform Group says HDT and GYH(T) are exempt from tax, and they still come off the claim. It also points out that the exemption doesn’t make a posting a temporary workplace.

Work through each tax year in this order:

1. Add up every business mile you drove that year, duty journeys included.
2. Price those miles at that year’s approved rates to get the maximum tax-free amount.
3. Take off the total the MOD paid you for them across MMA, HDT and GYH(T), and what remains is your relief.

Section 5 of HMRC’s P87 form follows the same order.

The MOD’s Discover My Benefits service lists MMA at 25p a mile for UK car journeys. Where every mile in the year was paid at that rate, the gap is 30p a mile on the first 10,000 in 2026/27 and 20p a mile in earlier years.

Above 10,000 miles, a mile paid at that rate leaves nothing to claim, because the approved rate and the MOD’s rate are both 25p.

Use the totals the MOD actually paid rather than working them out from a rate. HMRC wants to see a mileage log that gives each trip’s purpose plus its starting and finishing postcodes.

Two worked examples at 2024/25 and 2026/27 rates

Both examples assume you paid enough tax that year to cover the relief and had no other job expenses. The figures are illustrations, chosen to show how each step moves the result.

A basic-rate claim for 2024/25

A posting to a temporary workplace 23 miles from home, driven there and back on 190 days, works out like this:

• The journeys add up to 8,740 business miles, all inside the first 10,000.
• Priced at 45p, those miles come to £3,933.
• The MOD paid £1,600 towards those journeys, leaving £2,333 of relief.
• At 20%, that relief is worth £466.60.

With £2,500 or less to claim, this year can go through HMRC’s online service or a postal P87.

A higher-rate claim for 2026/27

This time the miles are all duty journeys, 12,500 of them, each paid at the MOD’s 25p:

• The first 10,000 miles at 55p come to £5,500, and the other 2,500 at 25p add £625, for an approved amount of £6,125.
• The MOD paid £3,125, which is 12,500 miles at 25p.
• The relief is £3,000, worth £1,200 at 40% if all of it falls within your higher-rate band.

The last 2,500 miles add £625 to both sides of the sum and cancel out. With relief above £2,500, this year goes on a Self Assessment return instead.

What an MOD mileage calculator may not see

A few things can sit outside an MOD mileage calculator’s sum, and each one can change your figure:

• Carrying colleagues earns no relief if you’re paid less than 5p a passenger mile, or nothing at all.
• Motorcycle and bicycle miles use 24p and 20p a mile with no drop after 10,000 miles, so price them separately from car miles.
• Fares, hotels and meals are separate job expenses, claimed only on whatever the MOD didn’t reimburse, and they count towards the same £2,500 total.
• Relief is capped at the tax you actually paid in the year, so a year with no tax paid gets nothing.
• Relief is given at the rate you pay, so a Scottish taxpayer should use their Scottish rate rather than 20% or 40%.

Mileage for a civilian job uses the same approved rates, and HMRC wants a separate mileage log for each employment. The mileage allowance relief calculator works through that side.

Before relying on the MOD tax refund calculator

The MOD tax refund calculator hands you a first draft of the figure, not the final one. Treat each tax year on its own: price the miles at 55p for 2026/27 or 45p for the years before, subtract every payment the MOD made towards those journeys, and apply your own tax rate to what’s left.

Keep the mileage log behind each figure, since it’s the evidence HMRC asks for. Check each year’s total against the £2,500 line to see which route it takes, and work forward from the earliest year the four-year limit still allows.

The guide on how to claim an MOD tax rebate sets out the posting test and each claim route in full.

Key Takeaways

• The MOD tax refund calculator estimates the tax value of your business miles but doesn’t subtract what the MOD paid, so that step is yours.
• Cars and vans earn 55p per business mile up to 10,000 miles in 2026/27, 45p up to 10,000 in earlier years, and 25p for every mile beyond that.
• Relief is the approved amount for the year minus the MOD’s mileage payments, including MMA, HDT and GYH(T).
• Where the MOD paid its 25p car rate, miles above 10,000 add nothing to relief, because both figures are 25p.
• Relief comes back at your own tax rate and is capped at the tax you paid that year.
• Each tax year is worked out on its own and can be claimed for up to four years after it closes.