What is an N tax code and why have I got one?

Tax code N allows couples in a civil marriage or registered partnership to transfer a portion of their personal tax allowance to their partner, helping to reduce their overall tax bill.

The N tax code is not an emergency code like the M1 tax code, for example. Emergency codes are temporarily used by HMRC when they don't have enough information about your earnings, whereas tax code N is used when one partner has chosen to transfer 10% of their unused personal allowance to the other through the Marriage Allowance scheme.

This can be especially helpful when one partner has a lower income or doesn’t use their full allowance. To qualify, both partners need to meet specific income requirements and apply through HMRC, making it a simple way to save as a couple.

How the N tax code works

The N tax code lets one partner transfer up to 10% of their unused personal allowance to the other, which can help lower their tax bill. The receiving partner’s tax code adjusts to reflect the added allowance, while the transferring partner’s code shows a slightly reduced allowance.

For example, if Partner A transfers £1,310, Partner B’s tax code will go up, reducing their tax. This setup works best if one partner’s income is below the personal allowance limit. However, if both partners earn above this limit, there may be no extra savings, as both already benefit fully from their allowances.

How to apply for the N tax code

To apply for tax code N, head to the Marriage Allowance section on HMRC’s website. You’ll need a few details handy, like your personal information, National Insurance numbers, and either a government gateway account or ID verification for first-time applicants.

If your relationship status changes, for example, due to separation or divorce, let HMRC know right away. This will help keep your tax code correct and avoid any mix-ups. Plus, if one partner’s income changes, you can adjust the allowance transfer to make the most of your tax savings.

Want to see if you’re owed a tax rebate? Get in touch, we’ll help you get back any money that’s rightfully yours!

Can I backdate Marriage Allowance claims?

Yes, you can backdate Marriage Allowance claims for up to four years. This means if you were eligible in past years but haven’t applied, you could get a refund for those missed savings. When you apply, HMRC will automatically include any backdated allowance if you qualify, which could give you a nice boost in your tax rebate.

Can unmarried couples apply for the N tax code?

No, unfortunately, tax code N is only available for married couples or those in a civil partnership. Unmarried couples aren’t eligible for the Marriage Allowance, so they can’t transfer their allowance under this scheme. It’s a benefit specifically for couples in legally recognised relationships, as defined by HMRC.

What is an N tax code and why have I got one?​

How the N tax code works

How to apply for the N tax code

Tax code N FAQs

Can I backdate Marriage Allowance claims?

Can unmarried couples apply for the N tax code?

What is an N tax code and why have I got one?