1257L-W1 or 1257L-M1

1257L is the most common tax code in England and Northern Ireland for the 2024/25 tax year, which started on 6th April 2024. You usually get a new tax code at the beginning of a tax year because this is often when changes to your personal allowance come into effect.

In Wales, the equivalent tax code is C1257L and in Scotland, it is S1257L.

What does it mean?

Nearly everyone is entitled to a tax-free personal allowance, which means that a certain amount of your earnings each year are paid to you without being taxed. If your tax code includes 1257L, it means your allowance will be £12,570.

It is given to you in equal portions throughout the year. For example, if you are paid weekly, your allowance is equivalent to £242 per week. If you’re paid monthly, it’s £1,048 per month.

Unless you’re in Scotland, any earnings over and above your personal allowance will be taxed as follows:

• 20% on earnings up to £37,700
• 40% on earnings between £37,701 and £125,140
• 45% on earnings above £125,140

So, what if your tax code is 1257L-W1 or 1257L-M1? Having W1 or M1 attached to your code means it is a non-cumulative tax code. The tax due on each payment is therefore determined without taking into account any tax you’ve already paid this year, or how much of your tax-free personal allowance has been used. In other words, it can result in you overpaying tax. If you see either of these codes on your payslip, you might want to double check if this is the best tax code for you.