HMRC Mileage Relief Guide

Getting your mileage money back from HMRC

A plain-English guide for care workers — what the £2,500 rule means, and exactly what you need to do.

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Important — Please Read

EasyMileage produces your mileage spreadsheet and nothing else. We are not tax advisors and we don't deal with HMRC on your behalf. This page explains what you need to do once you have your spreadsheet. If you're unsure about your personal tax situation, speak to an accountant or contact HMRC directly — details are at the bottom of this page.

1

Why can you claim mileage back?

If you use your own car to travel between clients for work — including getting to your first client of the day or back from your last — HMRC allows you to claim tax relief on those miles. This is called the Mileage Allowance Relief (MAR).

Basically, HMRC recognises that you are spending your own money to do your job, and you are entitled to get some of that back in the form of a tax refund.

Your EasyMileage spreadsheet is the evidence you need to make that claim. It shows every journey, with postcodes, miles, and the correct HMRC rate already calculated.

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The £2,500 rule — the one thing you need to know

There are three different ways to claim mileage relief from HMRC, and which one applies to you depends on whether your total claim for the year is above or below £2,500 and whether you've already put in your self assessment for the year you're claiming for.

£2,500
This is the cut-off point — based on your total expenses claimed

Under £2,500 — you can claim online using a simple form called P87.
Over £2,500 — you must complete a Self Assessment tax return.

An important detail: the £2,500 threshold is based on your total mileage expenses claimed — that is, the total figure on your EasyMileage spreadsheet. It is not based on the size of your eventual tax refund, which will be smaller (typically 20% of the claim value for basic rate taxpayers). So even if your expected refund is only a few hundred pounds, you may still need Self Assessment if the underlying mileage claim exceeds £2,500.

✓ Under £2,500

Simple — use Form P87

You claim online through your HMRC personal tax account using a form called P87. It takes around 15–20 minutes and you don't need an accountant.

⚠ Over £2,500

You need Self Assessment

You must register for and file a Self Assessment tax return. This sounds daunting but it is manageable — and the refund is worth it. We explain what to do below.

Self assessments need to put files by 31st January the year after the tax year. So if the tax year is 2023/2024, you have until 31st January 2025 to file.If you've already filed you have two options.

✓ 12 month filing amendment

Simple — amend your self assessment online

You've already filed your self assessment, but you have a further 12 month window to make amendments online. No penalty, straightforward.

⚠ Over 12 month amendment time

You need to submit an overpayment relief claim

Write to HMRC with an overpayment relief claim, still claimable, no penalty. There's a template at the bottom of the page.

Not sure which side of the line you're on? Check the Total Amount Claimed figure in the summary box at the bottom of your EasyMileage spreadsheet — that is the number to compare against £2,500. The crossover point is roughly 5,556 miles at the standard 45p rate.

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What does a typical claim actually look like?

Here's an example based on a typical care worker year, to help you understand what to expect:

Miles Rate (HMRC approved) Claim value
First 10,000 miles 45p per mile £4,500.00
Miles 10,001 – 17,000 25p per mile £1,750.00
Total claim value £6,250.00

The claim value is not the same as the tax refund. The refund depends on your tax rate (usually 20% for basic rate taxpayers):

Estimated tax refund (20% of £6,250) ≈ £1,250

This is an illustration only. Your actual refund depends on your specific mileage, your tax rate, and whether you paid the right amount of tax in the first place. But it shows why it's worth doing — this is real money that belongs to you.

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Under £2,500

How to claim using Form P87

This is the straightforward route. You'll need your EasyMileage spreadsheet handy before you start.

1
Create or log into your HMRC personal tax account

Go to gov.uk/personal-tax-account. You'll need your National Insurance number and a way to prove your identity (passport, driving licence, or payslips).

2
Select "Claim a tax refund"

Once logged in, look for "Income Tax" then "Claim a tax refund for employment expenses" — this leads you to the P87 form.

3
Enter your mileage details

You'll be asked for the total business miles you drove and the amount your employer reimbursed you (usually £0 if they paid you nothing). Use the totals from your EasyMileage spreadsheet.

4
Submit and wait

HMRC aim to process P87 claims within 12 weeks. The refund is paid directly into your bank account or adjusted through your tax code.

You can also claim for previous tax years — up to 4 years back. So if you haven't claimed before, you may be able to get money back going all the way to 2020/21.

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Over £2,500

How to claim via Self Assessment

If your total mileage claim is over £2,500, HMRC requires you to file a Self Assessment tax return instead of using the P87 form. Don't panic — this sounds more complicated than it is.

You only need to do this for the tax year your claim relates to. Doing a Self Assessment return doesn't mean you have to do one every year.

1
Register for Self Assessment

Do this at gov.uk/register-for-self-assessment. HMRC will post you a Unique Taxpayer Reference (UTR) number — this can take up to 10 working days, so register early.

2
Complete your tax return online

Log in to your HMRC personal tax account and complete the return. You'll need your total employment income (from payslips or your P60), your total mileage claim, and your UTR number.

3
Include your mileage as an employment expense

In the employment section of your return, there is a box for "Other expenses and capital allowances". This is where you enter your mileage claim total from your EasyMileage spreadsheet.

4
Submit before the deadline

Online returns for a given tax year must be submitted by 31 January of the following year. For example, for the 2024/25 tax year (April 2024 – March 2025), the deadline is 31 January 2026. Late filing carries an automatic £100 penalty.

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Keep your records

Hold on to your EasyMileage spreadsheet and your work rota for at least 5 years after the filing deadline. HMRC can ask to see your evidence at any point during this period.

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Already filed a return but forgot to include mileage?

You can amend a Self Assessment return you've already submitted — there is no penalty for doing this. You have 12 months from the original 31 January deadline to make changes online. After that window closes, you can still recover the money by writing to HMRC with an overpayment relief claim — this route is open for up to 4 years after the end of the tax year. Either way, you will not be charged for late filing because you are correcting an existing return, not filing a new one late.

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Common questions

My employer pays me something toward mileage — does that affect my claim?
Yes. You can only claim the difference between what HMRC allows (45p/25p per mile) and what your employer actually paid you. If your employer pays 20p per mile, you can claim the remaining 25p per mile for the first 10,000 miles. If they pay the full 45p or more, you cannot claim anything.
Can I claim for driving to my first client of the day?
Yes — as a domiciliary care worker, you almost certainly can. HMRC has a specific category called an itinerant worker, which applies to people who have no fixed base of work and travel between different locations as an inherent part of their job. Domiciliary care workers are explicitly cited by HMRC as an example. Because you are travelling as part of your work — not simply commuting to it — your journeys from home to your first client, and from your last client back home, are claimable. Your EasyMileage spreadsheet already includes these journeys.
I already filed a Self Assessment return for a previous year but didn't include mileage. Will I be penalised?
No — there is no penalty. You are not filing anything late; you are correcting a return you already submitted on time. If you are within 12 months of the original 31 January deadline for that year, you can amend your return online through your HMRC personal tax account. If that window has passed, you can write to HMRC and make what is called an overpayment relief claim — this is available for up to 4 years after the end of the tax year, so there is usually still time.
I haven't claimed for several years — can I still get that money back?
You can claim back up to 4 tax years. In 2025, this means you can go back as far as the 2021/22 tax year. Each year needs to be claimed separately.
Will contacting HMRC cause problems for me?
No. Claiming mileage relief is completely normal and HMRC expects it. Millions of employees claim it every year. You are not doing anything unusual or drawing attention to yourself — you are simply claiming money you are legally entitled to.
I need help — who can I speak to?
You can contact HMRC directly on 0300 200 3300 (Mon–Fri, 8am–6pm). Alternatively, Citizens Advice can help for free, or you can find a local accountant who often charge a fixed fee for straightforward claims.
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Amendment window closed

Template letter — Overpayment Relief Claim

If the 12-month online amendment window has passed, you need to write to HMRC by post. Use this template — fill in the highlighted sections, sign it, and send it with your EasyMileage spreadsheet and P60.

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Send by Royal Mail Signed For

This gives you proof that HMRC received your letter. Keep a copy of everything you send. HMRC can take up to 16 weeks to respond to overpayment relief claims — this is normal, so don't worry if you don't hear back quickly.

EasyMileage is not responsible for the outcome of your claim. This template is provided as a convenience and does not constitute legal or tax advice. You are responsible for ensuring the information you provide to HMRC is accurate.

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