What is Tax code?
Last verified 31 October 2026
A tax code is the code your employer or pension provider uses to work out how much Income Tax to take from your pay or pension. HMRC tells them which code to use, and you get one for each employment or pension you have.
Why it matters to landlords
Landlords with a salary or pension have a tax code for that pay. Rental profit is reported to HMRC through Self Assessment if your income is over £2,500 after allowable expenses, or over £10,000 before them. A wrong tax code can still change how much tax is taken from your pay in the year, so check it.
You can check your code online with an HMRC account, in the HMRC app, on your payslip or on a Tax Code Notice letter. You can sign up for paperless notifications so HMRC emails you when it changes. If you think the tax taken from your pay is wrong, your tax code may be incorrect and you should contact HMRC.
Example
Dan has a job and a rented flat that makes a £6,000 profit. He checks his tax code in the HMRC app when his payslip changes, then reports the £6,000 on his Self Assessment return. If the code looked wrong, he would contact HMRC rather than wait for the end of the year.
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