What does my tax code mean?

HMRC reviews your tax code, often in the autumn and early in the new year. The purpose of your tax code is to indicate how much of your earnings you can receive before tax is payable. It is normally the case that the larger the number in your tax code, the more of your earnings you can keep and the less tax you will pay. The exception to this is a tax code starting with K – see below.

Why does my tax code change?

Your tax code may change due to some of the following reasons:

You have filled in a self-assessment return and asked for underpaid tax to be collected through your PAYE tax code.
You have more than one job or source of income (eg second job/ pension/ freelance earnings)
Annual tax free allowance change

Decoding my tax code

The tax year for personal tax is from 6th April to 5th April. The standard personal allowance was £10,600 in 2015-16, which means that you don’t need to pay income tax until you earn more than £10,600. Your net tax allowances and reliefs (if you are eligible for any) are deducted from the personal allowance to arrive at your net allowance.

In most cases, your tax code will be your net allowance with the last digit replaced by L. The most common tax code in 2015-16 was 1060L – ie the personal allowance of £10,600. The personal allowance will increase to £10,800 for 2016/17 for most people so anyone with a tax code of 1060L at the moment will change to 1080L in April 2016.

What does my employer do with my tax code?

Your employer / pension provider will reverse the process above to work out the tax free amount in your pay. A tax code of 1200L would indicate a tax free allowance of £12,000. If you are paid monthly your employer will divide the allowance by 12 and pay the first £1,000 tax free each month. HMRC notifies your employer of any change to your tax code, but if you don’t think you are on the right tax code contact HMRC or your employer to check. Your employer does not receive the reason for any adjustment to your tax code

What does M1 mean in my tax code?

W1 (week 1) and M1 (month 1) are emergency tax codes and appear at the end of an employee’s tax code, for example ‘577L W1’ or ‘577L M1’. If you have an M1 code your tax is calculated with reference to the current pay period only and not the cumulative pay to date.

The reason for this tax code is typically that you have started a new job during the tax year and your employer does not have the balance of other earnings earlier in the year. The W1/M1 indicator is normally removed once HMRC has caught up with your new employment and will be removed when the payroll year resets on 6th April each year.

Emergency tax codes are temporary. HMRC will usually update your tax code when you or your employer give them your correct details. If your change in circumstances means you have not paid the right amount of tax, you’ll stay on the emergency tax code until you’ve paid the correct tax for the year.

Why is my tax code different for different employers?

Your tax free allowance is for you as an individual and not given to each employment / source of income. If your current employer uses the standard tax code (1060L for 2015-16) they will use up all your tax free allowance of £10,600. If you start a second part time job, you will have no tax free allowance left and your tax code will be different to 1060L.

Special tax codes

New tax codes for Marriage Allowance

Are you thinking of starting your own business?

If you are thinking of starting your own business have a look at the Alterledger article on claiming tax deductions for pre-trading expenses.

Contact Alterledger

For more information on tax returns and employment, please contact Alterledger.