How to Check Your Tax Code Is Correct in the New Year

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.

What a Tax Code Does

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:

• How much tax you pay
• Your take-home pay
• The figures that eventually appear on your P60

That’s why checking it early in the year matters.

Where to Find Your Tax Code

You can usually find your current tax code in three places:

• On your latest payslip
• On your P60 from the previous tax year
• In your HMRC Personal Tax Account online

If you’ve started a new job, changed hours, or had benefits added, your code may have been updated automatically.

Common Tax Codes You Might See

• 1257L – Standard code for most employees
• BR – All income taxed at basic rate (often second jobs)
• D0 – All income taxed at higher rate
• K – You owe tax or receive taxable benefits
• NT – No tax deducted

A change doesn’t always mean something’s wrong — but it’s always worth checking.

Signs Your Tax Code Might Be Wrong

You should double-check your code if:

• Your take-home pay changes unexpectedly
• You’ve started or left a job recently
• You have more than one employer
• You receive company benefits (car, healthcare, etc.)
• You were on maternity, sick, or unpaid leave last year

Even a small error can add up over several months.

How to Check Your Tax Code Properly

Step 1: Compare it with your situation

Ask yourself:

• Do I have one job or more than one?
• Do I receive taxable benefits?
• Did I leave or start a job recently?

If your code doesn’t match your circumstances, move to step two.

Step 2: Log in to your HMRC Personal Tax Account

There you can:

• View your current and past tax codes
• See what income HMRC thinks you earn
• Report changes or corrections

Step 3: Contact HMRC if needed

If something’s clearly wrong, HMRC can usually fix it quickly.
Once corrected, your employer will automatically apply the new code in payroll.

Why This Matters for Your P60

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:

• Less chance of overpaying tax
• Fewer surprises at year-end
• A cleaner, more accurate P60 in April/May

Good Habit for the New Year

Make it routine:

• Check your tax code in January
• Recheck after any job change
• Compare your final payslip to your P60 each year

It’s one of the easiest ways to stay on top of your finances.

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