Last reviewed: January 2025

A lot of couples in the UK aren’t getting the most from their Marriage Tax Allowance. Are you one of them? A wrinkle in the tax rules means that, if they’re eligible, married couples can save £252 in tax each year. You can see if one of you is using the allowance because you'll have the tax code 1383M for receiving it and tax code N for granting it to your partner. If you missed the boat on this in previous years, you can even backdate your Marriage Allowance claim so you don't lose out! Let’s take a look at what the Marriage Allowance system’s all about.