What is tax code 1383M?
Employees in the UK have a tax code which the payroll department will use to calculate your tax. If you are a sole trader, partnership or limited company director, you won’t need a tax code for self-assessment, unless you also have employed income. Your tax code can be confusing, so read on to find out more about how tax codes work and what it means if your tax code is 1383M.
Understanding tax codes
UK tax codes are a combination of numbers and a letter.
The tax code denotes how much of your income is tax-free. In other words, how much personal allowance you are entitled to.
What do the numbers mean on a tax code?
The numbers on a tax code tell your payroll department how much of your pay is tax free. The most common tax code is 1257L. To work out the tax-free portion of your pay, add a zero to the end of the numbers. So tax code 1257L means the person gets £12,570 in personal allowance.
What do the letters mean on a tax code?
The letters on the tax code can denote a wide range of things. For example, the L in 1257L shows that the employee qualifies for the standard personal tax allowance.
Here’s a table showing the commonly used letters with examples:
| Tax Code Letter | Explanation | Example |
| L | Standard tax-free personal allowance | 1257L |
| M | Marriage Allowance: received 10% of partner's Personal Allowance | 1383M |
| N | Marriage Allowance: transferred 10% of Personal Allowance to partner | 1131N |
| T | Other calculations used to determine Personal Allowance | 1200T |
| 0T | Personal Allowance used up or not enough details for a tax code | 0T |
| BR | All income taxed at basic rate | BR |
| D0 | All income taxed at higher rate | D0 |
| D1 | All income taxed at additional rate | D1 |
| NT | No tax to be paid on this income | NT |
| S | Scottish taxpayer, income taxed at Scottish rates | S1257L |
| C | Welsh taxpayer, income taxed at Welsh rates | C1257L |
| K | Indicates tax owed from previous year or taxable benefits exceed Personal Allowance |
K475 |
| W1 or M1 | Emergency tax code (Week 1 or Month 1 basis) | 1257L W1 |
| X | Emergency tax code | 1257L X |
| S0T | Scottish taxpayer with Personal Allowance used up | S0T |
| C0T | Welsh taxpayer with Personal Allowance used up | C0T |
| SBR | Scottish basic rate | SBR |
| SD0 | Scottish intermediate rate | SD0 |
| SD1 | Scottish higher rate | SD1 |
| SD2 | Scottish top rate | SD2 |
| CBR | Welsh basic rate | CBR |
| CD0 | Welsh higher rate | CD0 |
| CD1 | Welsh additional rate | CD1 |
What is the tax code 1383M?
Tax code 1383M means that you have received 10% of your spouse’s personal allowance. It’s also known as the Marriage Allowance. It can be advantageous to receive extra personal allowance from your spouse, saving you up to £252 in tax per year.
What are the eligibility criteria for tax code 1383M?
To receive the Marriage Allowance, you must meet the following eligibility criteria:
- You must be married or in a civil partnership. Living together does not qualify.
- Both individuals must be born on or after 6 April 1935. If one partner was born before this date, you may be eligible for the Married Couple’s Allowance instead.
- The lower-earning partner must have an income of £12,570 or less (for 2024/25 tax year).
- The higher-earning partner must be a basic rate taxpayer, typically earning between £12,571 and £50,270 (or £43,662 for Scottish taxpayers).
- Neither partner should pay income tax at a rate higher than the basic rate (or intermediate rate for Scottish taxpayers).
- You must be living with your spouse or civil partner. However, there are exceptions for temporary separations due to illness, work, education, or other specific circumstances.
- The lower-earning partner must apply for the Marriage Allowance.
- Claims can be backdated for up to four years25.
- You cannot claim both Marriage Allowance and Married Couple’s Allowance. If you’re eligible for both, Married Couple’s Allowance usually provides a higher benefit
Why has my tax code changed to 1383M?
If your spouse has applied for you to receive 10% of their personal allowance, your code will change from 1257L to 1383M denoting the extra Marriage Allowance.
Why do I have tax code 1131N?
Your tax code will change to 1131N if you elect to pass 10% of your personal allowance to your spouse.
Contact Adams Accountancy
Are you sure your tax code is correct?
Tax codes can be confusing, especially if you don’t know why your code has been changed. If you’d like to understand your tax code better or discuss your personal tax situation, we’d love to hear from you. Contact us for a free, no-obligation chat today.
