
January is when a lot of people notice something doesn’t quite add up with their pay. Maybe your take-home pay has changed, or your tax deduction looks different from December. In many cases, the reason is simple: your tax code has changed.
Here’s how to check your tax code at the start of the year — and what to do if it’s wrong.
Your tax code tells your employer how much Income Tax to deduct from your pay.
It’s set by HMRC, not your employer, and it’s used every time payroll runs.
Your tax code affects:
That’s why checking it early in the year matters.
You can usually find your current tax code in three places:
If you’ve started a new job, changed hours, or had benefits added, your code may have been updated automatically.
A change doesn’t always mean something’s wrong — but it’s always worth checking.
You should double-check your code if:
Even a small error can add up over several months.
Ask yourself:
If your code doesn’t match your circumstances, move to step two.
There you can:
If something’s clearly wrong, HMRC can usually fix it quickly.
Once corrected, your employer will automatically apply the new code in payroll.
Your tax code affects every payslip — and those figures roll up into your P60 at the end of the tax year.
Catching errors in January means:
Make it routine:
It’s one of the easiest ways to stay on top of your finances.
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