HMRC has issued a warning to employees across the UK to carefully check their March payslips due to significant tax code changes for the 2025/26 tax year. 

With potentially millions of people affected, it’s crucial to ensure that the correct tax code is applied to avoid any unexpected tax bills.

Why are tax codes changing?

There are several reasons why your tax code could change, including:

• Changes in employment e.g. you’ve changed jobs or employment status.
• If your salary has increased or decreased, it may affect your tax.
• Your company benefits (like a company car) might have changed so your tax code needs updating. 
• Alterations to your pension contributions can impact your tax code.

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How to check your tax code

There are a few different ways you can check your tax code, including logging into your Personal Tax Account under the Pay As You Earn section or by reviewing recent payslips.

How do I know if I’m on the right tax code?

Looking at your tax code might feel daunting because it’s a mix of numbers and letters, but they actually mean something very specific. We’d recommend checking out our expert guide “Your tax code explained” for more information.

If you want to check what income tax you should be paying, we have a free income tax calculator that will quickly calculate what you owe and what you should take home. 

Important note for those both self-employed and employed

Working out your tax code can be trickier if you pay tax owed from self-employment via your employee earnings. But don’t worry! We have plenty of resources to help. We recommend checking out our guide “Freelancing on the side: what tax do I pay?” and our free self-employed tax calculator. The free tax calculator allows you to input income from both employed and self-employed methods to help you work out what your take home pay is.  

Don’t forget to check your tax code

Even if you haven’t received notification from HMRC, it’s worth checking your tax code to ensure you’re on the right one. Remember, reviewing your payslips and tax code now could save you from unexpected bills down the line!

If you’re unsure, you can contact HMRC directly. However, be aware that HMRC lines are much busier around peak times, such as the end and beginning of tax years or the Self Assessment deadline.

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