Methodology

How we calculate

A single place for the numbers behind the tools. Everything here is for the 2026/27 tax year and cited to the primary source.

Income tax and National Insurance (England, Wales, NI)

Personal allowance £12,570, tapered away between £100,000 and £125,140. Basic rate 20% to £50,270, higher 40% to £125,140, additional 45% above. Employee National Insurance 8% between £12,570 and £50,270, then 2%. Scotland uses different income tax bands and is handled separately.

State Pension and voluntary NI

Full new State Pension based on 35 qualifying years. One voluntary Class 3 year and the extra pension it buys are taken from the current gov.uk rates. Because gov.uk cannot confirm whether a specific year raises your own pension, our tool is a guide to the maths and always points you to check your forecast.

Stamp duty (SDLT, LBTT, LTT)

England and Northern Ireland use SDLT bands; Scotland uses LBTT; Wales uses LTT. First-time-buyer relief and the additional-property surcharge (5% SDLT, 8% Scottish ADS, higher rates in Wales) are applied per nation.

Every rate on this page is re-verified against the official source at each review. The last review date is shown on each tool and in the footer.