UK Tax Glossary
Clear, plain-English definitions of 25 key UK tax terms. From PAYE and Personal Allowance to fiscal drag and inheritance tax — understand the language of UK taxation.
All figures are for the 2025/26 tax year unless otherwise stated.
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P45
A certificate issued by your employer when you leave a job, showing your pay and tax to date.
Salary Calculator →P60
An end-of-year certificate from your employer showing your total pay and tax deducted.
Salary Calculator →PAYE (Pay As You Earn)
The system HMRC uses to collect income tax and National Insurance directly from employees' wages.
Salary Calculator →R
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Salary Sacrifice
An arrangement where you give up part of your salary in exchange for a non-cash benefit, saving tax and NI.
Salary Sacrifice Calculator →Self Assessment
The process of filing your own tax return with HMRC, typically required for self-employed people and those with complex tax affairs.
Self-Employed Tax Calculator →