Tax code (PAYE)

In the UK, every person paid under the PAYE scheme is allocated a tax code by HM Revenue and Customs. This is usually in the form of a number followed by a letter suffix, though other 'non-standard' codes are also used. This code describes to employers how much tax to deduct from an employee. The code is normally based provided to HMRC by the taxpayer or their employer.

Tax codes are usually adjusted once a year to take into account any changes made in the National Budget, but can be altered more often to reflect an employee's circumstances. Tax codes can be changed if someone has paid too much or too little tax the previous tax year, if an employee receives state benefits, or has non-PAYE income (for example, self-employed earnings). Changes in a tax code are to ensure the employee has paid the correct amount of tax by the end of each tax year.

Tax codes are passed between periods of employment by a P45, which is generated when a person leaves a job. If a P45 is mislaid or not supplied at the end of a period of employment, a P46 can be filled out in order to determine which tax code is applicable to a person. Between submitting a P46 and receiving the correct tax code from HM Revenue and Customs, an employer can apply the emergency tax code on a week 1 basis. In this case, tax will be calculated as if the employee is working in the first week of the tax year, and all previous earnings are ignored.

At the end of each tax year employers are required to send out a P60 which documents the total earnings and tax a person has paid within that tax year. However, this only applies if the employee was still in employment (or on the payroll) on 5. April (the last day of the tax year).