How do I know I’m due a tax rebate?

Being due a tax rebate means that for whatever reason, you paid more income tax than you were supposed to (HMRC makes mistakes too, surprise, surprise!). 

At the end of the tax year, you will receive a P8100 which lets you know if you’re due a tax rebate. The good news is that now HMRC has to give you back any overpaid tax.

If HMRC does not automatically refund your overpaid tax, you will have to claim it yourself by contacting HMRC – either way, nothing feels better than a bit of extra cash rolling in unexpectedly.

Find out when you are due a tax rebate and how to claim a refund below.

When am I due a tax rebate?

This will differ depending on whether you are full-time employed or self-employed.

Full-time employed (PAYE):

• You start a new job, and you get an emergency tax code
• HMRC sends the wrong tax code to your employer
• Your employer didn’t use the correct tax code
• You have more than one PAYE job
• Your company benefits change: certain employee perks (company car, health insurance, etc.) are taxable and can change your tax code
• If you had some expenses for work, for example washing your uniform or clothing, etc. You can claim these back

Self-employed:

• When you make Payments on Account for the following year. Because when you make a Payment on Account HMRC estimates this year’s income based on what you earned last year, sometimes you might end up overpaying
• If you’re a construction worker and have registered for CIS (Construction Industry Scheme): your contractor will deduct 20% tax from what you earn. Most of the time you’re due a £1,000-2,000 rebate

Other less common situations:

• You can sometimes pay too much tax on savings interest
• You’re a pensioner with more than one pension
• Your state benefits change
• You stopped working

How do I check if I’m due a tax rebate?

• Full-time employed: check your tax code (here is how to read it and what those numbers and letters mean)
• Self-employed: try calling HMRC. If you’re a CIS worker, you can also use our CIS tax rebate calculator

How do I claim it?

Claiming a tax refund depends on your situation:

• If you’re a PAYE or pensioner: try contacting HMRC first – they can change your tax code (be sure to have your National Insurance Number to hand when calling HMRC)
• If you’re self-employed: you’ll have to submit a Self Assessment tax return to get your rebate

Bare in mind that a tax rebate is different from tax relief.

I know I’m due a rebate, but where is it?

Ah, the age-old question. It all depends on HMRC. Once your Self Assessment is filed, your accountant doesn’t control when you receive your rebate. Usually, you’ll have it within 12 weeks but again, it all depends on HMRC. If you haven’t received your refund within this timeframe, it’s best to get in touch with HMRC for an update. 

Watching out for scams 🚨

In June 2025, HMRC issued a warning about a sharp rise in fake tax rebate messages. Scammers have been posing as HMRC, texting or emailing people to say they’re “due a rebate”, all to steal personal info.

More than 130,000 scam messages were reported in just one year 🤯, so it’s worth double-checking before clicking on anything.

Here’s how to stay safe:

• Don’t click on links in unexpected texts or emails
• HMRC will never ask for your bank details via text or email 🔒
• Only check your rebate through your Personal Tax Account
• If you’re unsure, call HMRC directly on 0300 200 3300

Think you’ve been targeted?

Report it to Action Fraud and contact your bank straight away. You can also forward suspicious emails to HMRC.

Anything else I should know?

Don’t forget, there’s also a possibility that you’ve paid less tax than you need to. Not to worry, most of the time it won’t be your fault but if there are changes you need to report, make sure you do your best to let HMRC know as soon as you can.

If you’ve over or underpaid your taxes, HMRC will send you a P800 or Simple Assessment tax calculation at the end of the tax year. You won’t receive either of these if you’re registered for/have already filed your Self Assessment. Instead, your final bill will be adjusted by HMRC to take it into account.

Get in touch with HMRC for more information on where your rebate is.