How do I know if I've overpaid tax?

Common reasons for overpaid tax include: being on the wrong tax code (especially if you started a new job or have multiple jobs), being taxed on Emergency Tax when starting a new job, not claiming your full personal allowance, overpaying after leaving a job mid-year, and not claiming tax relief you're entitled to (e.g. working from home, professional subscriptions). HMRC should send you a P800 tax calculation after the end of each tax year showing if you've overpaid — but not everyone receives one, especially if you're on Self Assessment.

How long does a tax refund from HMRC take?

If HMRC sends you a P800 showing you've overpaid, you can claim online and receive the refund within 5 working days (by bank transfer). If you request a cheque, it takes 6–8 weeks. If you're claiming through Self Assessment, the refund is usually processed within 2–6 weeks of filing your return. If HMRC needs to investigate, it can take longer. Universal Credit claimants should be aware that a tax refund counts as income in the month received.

Can I claim a refund for previous years?

Yes — you can usually claim a tax refund for the last 4 tax years. For example, in 2026/27 you can still claim for 2022/23, 2023/24, 2024/25, and 2025/26. If you've been on the wrong tax code for several years, you could be owed thousands. Contact HMRC or use Self Assessment to make a claim. There is no time limit on claiming if you submitted a Self Assessment return and overpaid.

Is my tax refund taxable?

No — a tax refund is simply a return of money you shouldn't have paid in the first place. It is not treated as income for tax purposes. However, if you receive Universal Credit, a tax refund may be counted as income in the assessment period it's received, which could reduce your UC payment for that month. If this applies to you, consider the timing of your refund claim.

HMRC Tax Refund Guide — How to Claim Back Overpaid Tax | PocketWise

Millions of people overpay tax every year — often without realising. Here’s how to check if you’re owed a refund and how to claim it.

Common Reasons for Overpaying Tax

Reason	How it happens
Wrong tax code	Your tax code determines how much tax-free income you get. If it’s wrong, you pay too much
Emergency tax	New job, new employer doesn’t have your tax details — you’re taxed at a higher rate
Left a job mid-year	You may have paid too much tax because PAYE assumed you’d work the full year
Multiple jobs	Personal allowance split incorrectly between employers
Unused personal allowance	Didn’t earn enough to use your full £12,570 allowance
Didn’t claim Marriage Allowance	Worth up to £252/year (from 2025/26)
Didn’t claim tax relief on expenses	Working from home, professional subscriptions, uniform allowance
Pension tax relief not claimed	Higher/additional rate taxpayers need to claim the extra relief via Self Assessment
Redundancy taxed incorrectly	First £30,000 should be tax-free
Savings income over-taxed	Bank deducted tax but your savings allowance covers it

How HMRC Tells You About Overpaid Tax

P800 Tax Calculation

Detail	Information
What it is	A letter/notification from HMRC showing your tax calculation for the year
When it’s sent	Usually between June and November after the end of the tax year
What it shows	Whether you’ve overpaid or underpaid tax
How you’re notified	Letter or notification on your Personal Tax Account
Do you always get one?	No — only if HMRC’s figures show a discrepancy

Simple Assessment (PA302)

Detail	Information
What it is	A tax bill sent to people who don’t file Self Assessment
Who receives it	Often pensioners or people with non-PAYE income
What to do	Check it’s correct — pay any underpayment, or contact HMRC if you disagree

How to Check If You’ve Overpaid

Method	How
Personal Tax Account	Sign in at gov.uk — check your tax code and calculation
Tax code check	Your payslip shows your tax code. Standard for 2026/27: 1257L
P60 (end of year)	Shows total tax paid — compare with what you should have paid
P45 (if you left a job)	Shows earnings and tax paid when you left — check for errors
Self Assessment	Filing a return automatically calculates if you’ve overpaid

Check Your Tax Code

Tax code	Meaning	Correct for
1257L	Standard personal allowance (£12,570)	Most employees with one job
BR	All income taxed at 20% (no personal allowance)	Usually means HMRC doesn’t know your correct tax situation
0T	No personal allowance	Emergency tax or undisclosed income
K code	Tax code starts with K — you owe tax from a previous year	Code is correct but worth checking
W1/M1 (emergency)	Non-cumulative — each pay period taxed in isolation	Temporary — should resolve when HMRC gets your details

If your tax code is wrong, contact HMRC immediately or update your Personal Tax Account.

How to Claim a Refund

Method 1: Online via P800

Step	Action
1	Sign in to your Personal Tax Account at gov.uk
2	Check if you have a P800 showing a refund
3	Click “Claim your refund”
4	Enter your bank details
5	Refund received within 5 working days

Method 2: By Phone/Post

Step	Action
1	Call HMRC: 0300 200 3300
2	Explain that you believe you’ve overpaid tax
3	HMRC reviews your records
4	If a refund is due, they send a cheque (6–8 weeks) or arrange bank transfer

Method 3: Self Assessment

Step	Action
1	File your Self Assessment tax return
2	The return automatically calculates if you’ve overpaid
3	If you’re owed a refund, it’s processed after you submit
4	Refund usually within 2–6 weeks

Method 4: In-Year Refund (Left a Job)

Step	Action
1	If you’ve left a job and aren’t starting another one (or not for 4+ weeks)
2	Complete form P50 — claim a tax refund for the current year
3	Submit with Parts 2 and 3 of your P45
4	HMRC processes the refund

Specific Refund Situations

Emergency Tax Refund

Situation	What to do
New job, being taxed on BR or 0T	Give your new employer your P45 from your previous job
No P45 available	Complete HMRC’s “New Starter Checklist” form
Still on emergency tax after 2 months	Contact HMRC — call 0300 200 3300 or check Personal Tax Account
Refund timing	Usually adjusted in your next few pay packets once corrected

Marriage Allowance Refund

Detail	Information
What it is	Transfer £1,260 of personal allowance to your spouse/civil partner
Tax saving	Up to £252/year (2025/26)
Can you backdate?	Yes — up to 4 years
Maximum backdated refund	Up to ~£1,260 (4 years × £252 + current year)
Who can claim	Non-taxpayer or basic rate taxpayer transfers to basic rate spouse
How to apply	gov.uk/marriage-allowance

Working from Home Tax Relief

Detail	Information
Flat rate relief	£6/week (no receipts needed) — worth £1.20/week (20% of £6)
Annual saving	£62.40 (basic rate) or £124.80 (higher rate)
How to claim	Via Personal Tax Account or Self Assessment
Can you backdate?	Yes — up to 4 years

Professional Subscription Tax Relief

Detail	Information
What it is	Tax relief on professional body membership fees
Who qualifies	Anyone paying fees to an HMRC-approved professional body
Examples	Nursing and Midwifery Council, RICS, CIPD, Law Society, BMA
Tax relief	20% of the subscription fee (or 40% for higher rate taxpayers)
How to claim	Form P87 or Self Assessment

How Long Refunds Take

Refund method	Timeline
P800 online claim (bank transfer)	5 working days
P800 cheque	6–8 weeks
Self Assessment overpayment	2–6 weeks
Marriage Allowance backdated	4–8 weeks
P50 in-year refund	4–6 weeks
HMRC corrects your tax code	Adjusted in next pay packet(s)

Beware of Tax Refund Scams

Red flag	Why it’s a scam
Text/email saying “you’re owed a tax refund”	HMRC never notifies by text or email about refunds
Asked to click a link to claim	HMRC will never ask you to click through to provide bank details
Asked for bank details via email	Always access your refund through gov.uk directly
Phone call demanding immediate action	HMRC communicates by post or through your Personal Tax Account

Always go directly to gov.uk — never click links in texts or emails claiming to be from HMRC.

HMRC Tax Refund Guide — How to Claim Back Overpaid Tax

Contents