Tax terms, decoded
UK tax is full of acronyms and jargon: PAYE, UTR, ITSA, BIK, AMAP. This glossary turns each one into a clear, one-line definition you can actually use, with links to the calculators and guides that put the term into practice.
Browse all 145 terms
Select a term for its full plain-English definition, worked examples and related tools.
0 to 9
A
B
C
D
L
N
P
S
T
Frequently asked questions
What is a UK tax glossary?
A tax glossary is a plain-English reference that defines the words, acronyms and HMRC terms you meet when dealing with UK tax. This glossary covers everything from PAYE and tax codes to Self Assessment, National Insurance, VAT and Making Tax Digital.
Which tax terms should I learn first?
Start with the basics that appear on your payslip and tax return: Personal Allowance, tax code, PAYE, gross income, net income and National Insurance. From there, explore the terms relevant to your situation, such as Self Assessment for the self-employed or VAT for growing businesses.
Are these definitions up to date for 2026/27?
Yes. Every definition is aligned with HMRC guidance and the rates and thresholds for the 2026/27 tax year. Where figures change between tax years, the relevant pages are updated.
Stop guessing what tax words mean.
TapTax imports your bank statements, categorises expenses automatically, and submits quarterly updates to HMRC. Free plan, no card required.
Get started free- Tax calculators
Every free calculator, grouped by the job it does.
Where these definitions come from
Official guidance on GOV.UK.