What’s a tax rebate (P800 refund) and how do I claim one?

Have you ever seen a brown envelope from HMRC in your mailbox and felt a bit nervous? 

It’s totally common. But if the letter has P800 printed at the top, you might be in luck. A P800 form is HMRC’s way of telling you that your tax calculations for the year didn’t quite add up (it happens). And more often than not, that means they owe you money. 

However, P800s are only sent to people taxed through PAYE. This means that if you’re an employee or you take a salary through a limited company, this applies to you. 

If you’re a sole trader who pays tax through Self Assessment, you won’t get sent a P800. Your UK tax rebate works differently, and we’ll cover how further down in the article.

Either way, let’s get you sorted. Here’s why you might get a P800 and how you go about claiming a refund.

Key takeaways

• A P800 is a tax calculation letter from HMRC. It’s not a bill, and it’s not something to worry about
• P800s only apply to PAYE income. Self–employed sole traders claim tax rebates through Self Assessment instead
• You can usually claim online and have your refund in your bank within about five working days

If any of your income runs via PAYE (usually this applies to company directors taking a salary or employees), HMRC reconciles your tax position annually after the tax year ends on 5 April. 

If the numbers don’t match what you should’ve paid, they’ll get in touch.

You might be due a tax rebate if:

• You changed jobs partway through the year and ended up on an emergency tax code
• You had more than one job or income source 
• You stopped working partway through the tax year
• Your tax code was wrong for part of the year (this happens more than you think)
• You claimed marriage allowance and this hasn’t been reflected correctly
• You paid job–related expenses that qualify for tax relief (e.g. professional subscriptions or uniform)

What is an emergency tax code? An emergency tax code is a temporary code HMRC gives you, often when you start a new job without a P45. It assumes you’re not entitled to your full tax–free allowance, which means you temporarily pay more tax than you owe until HMRC updates your details. 

If any of these reasons apply to you, don’t worry. It doesn’t mean you’ve done anything wrong. 

The PAYE system is designed to calculate your tax as you go, but it’s rarely perfect. 

A P800 is HMRC catching up and squaring things off.

So, let’s get to the million–pound question: what is a P800? 

You can think of a P800 as HMRC’s end–of–year report card for your tax. 

Once they’ve gathered all the data from employers, pension providers, and their own records, they compare what you paid against what you should’ve paid. 

The P800 sets out the difference.

HMRC P800 letters typically arrive through the letterbox between June and November, though it can occasionally be later if HMRC needs more time to pull everything together. 

Each letter includes:

• The tax year it relates to
• Your total income and the tax you paid on it
• Whether you’ve overpaid (refund due) or underpaid (tax owed)
• A reference number you’ll need to claim online

Good question. Basically, HMRC compares the income and tax figures reported by your employer or pension provider (which is the same data that shows up on your P60) against what you should have paid based on your personal allowance and tax code for that year. 

It’s always worth checking these figures against your own P60 or P45 before accepting the tax refund, because the calculation is only ever as good as the data HMRC has on file. Mistakes do happen!

If something looks off, it’s a good idea to get in touch with HMRC and explain what you think is wrong.

Let’s imagine that you’ve got the letter, you’ve checked the figures, and they look correct. Here’s what to do next.

If you’re due a refund:

1. Sign in to your personal tax account on GOV.UK (or via the HMRC app)
2. Have your P800 reference number and National Insurance number to hand
3. Choose to claim your tax rebate online via bank transfer, or request a cheque 
4. Enter your UK bank details (sort code and account number) if you’re going the bank transfer route

Tip: Bank transfers are the fastest option here. Most people see the money in their account within about five working days. If your letter tells you a cheque is being sent, it’ll usually arrive within 14 days of the date on the letter

Worth noting: HMRC no longer sends cheques automatically (this was discontinued in 2024). So, if your Form P800 says you need to claim online, this is the route you need to take.  

It’s also worth noting that your money isn’t lost if you don’t act straight away. It’ll just sit on your tax record until you claim it — and you have a four–year window to do so(more on that below).

If you’ve underpaid:

First and foremost: don’t panic. Underpaying happens, and it’s usually manageable. 

If you owe less than £3,000, HMRC will collect what you owe automatically by adjusting your tax code the following year. 

This spreads the cost across your payslips rather than taking a lump sum. 

If the amount you owe is higher than £3,000, or you’d rather pay it off directly, you can contact HMRC to arrange that.

In a nutshell: if you’re a sole trader without any PAYE income, you won’t get sent a P800.

HMRC’s Self Assessment system handles your tax, and anything you’ve overpaid gets picked up when you file your return.

Here’s how it works:

• If you’ve overpaid tax through Self Assessment, HMRC will show this once your return is processed.  You can request the repayment directly through your online HMRC account
• If you spot a mistake after filing (for example, you’ve forgotten to add some expenses), you can amend your return

Tip: You have 12 months from the 31 January filing deadline to do this

• If you’re a director who takes both a salary through PAYE and dividends or profits reported via Self Assessment, you could end up dealing with both a P800 (for the PAYE side) and a Self Assessment repayment (for everything else) in the same year 

If you’re working as a sole trader but are ready to formalise your business into a limited company (congrats, btw), our company registration process is quick, easy and designed for small business owners. 

Once you’ve made a claim, timings depend on how you’re getting paid:

• Bank transfer: around five working days
• Cheque (automatic): within 14 days of the letter date
• Cheque (requested by phone): can take up to six weeks

If nothing’s turned up after these windows, it’s a good idea to check your personal tax account before getting in touch with HMRC. Sometimes the payment’s been logged in your account but it hasn’t hit your bank account yet.

You’ve got four years from the end of the relevant tax year to make a claim.

After that, the window closes for good. 

Right now, that means you can still claim for the 2022/23 tax year up until 5 April 2027, with 2023/24, 2024/25, and 2025/26 all still open, too.

If you’ve got an old and unclaimed P800, it’s worth checking the tax year on it against these dates. Remember, the sooner you claim, the sooner it’s sorted.

Yes. HMRC doesn’t catch everything, so it’s very possible to be owed money without getting a letter about it. 

Here are a few common situations:

• You’ve paid for allowable work expenses: mileage, tools, or work–related subscriptions (things that HMRC wouldn’t know about)
• You’ve overpaid: this is commonly because of an emergency tax code that was never corrected
• You’ve had savings interest taxed incorrectly: another common one

In these cases, you can check your tax situation in your online tax account or claim expenses directly through a P87 form. 

It’s a bit more effort than waiting for a letter, but if you think (or know) you’re owed a refund, it’s worth the ten minutes it takes to check.

A P800 is just HMRC squaring up your tax. And, more often than not, it means that a little bit of extra cash is coming your way. 

Just remember to check the figures, then claim it online (if you can) and you should see it hit your bank account within a week. 

In the meantime, if you’re looking for an easy way to keep on top of your business finances, our business bank account comes with built–in accounting tools to help you with your tax admin. And, if you want to keep every deadline in view, our guide to business tax deadlines can help you get organised. For business guidance, head over to our resource hub. 

Log in to your personal tax account on GOV.UK or the HMRC app and look for any flagged overpayments under your PAYE or income tax section. Here, you can review your situation for previous years, even if HMRC hasn’t sent you a P800.

No. HMRC issues P800s automatically once they’ve reconciled your PAYE records after the tax year ends, usually between June and November. You don’t need to request one. If you think you’re owed a refund and haven’t had a letter, you can check your personal tax account directly instead of waiting.

This doesn’t necessarily mean you’re not owed anything. HMRC’s system doesn’t catch every discrepancy. If you believe you’ve overpaid, you can check your personal tax account or contact HMRC directly to ask them to review your tax situation for the relevant year.

No, never. HMRC only sends P800 tax calculations by post or through your personal tax account and the HMRC app — not by email or text. If you get an email or text claiming to be from HMRC about a tax refund, it’s very likely a scam. Don’t click any links and go straight to GOV.UK instead.