Glossary

Plain-English definitions, alphabetically.

How to use this glossary

Every term here is written for someone who's just hit it in a payslip, mortgage offer, or HMRC letter and needs the answer in under 60 seconds. Each entry includes a plain-English definition, why it matters in practice, and — where it's useful — a worked numerical example using realistic UK figures. Where a calculator exists for that concept, the entry links straight to it.

Most-looked-up terms

By traffic, the most-consulted entries on this site are marginal tax rate, personal allowance, SDLT, APR, and AER. If you only have time for five, those five cover most everyday UK money decisions.

What's not here

This glossary is deliberately tight: only terms we've found people actually search for, in the contexts they actually search for them. We don't pad it with archaic legal jargon or US-only financial vocabulary. If a term is missing and you think it shouldn't be, it's worth flagging — the index is updated roughly monthly.

All terms