IR35 Guides for UK Contractors

The April 2026 small company threshold changes shifted IR35 responsibility to 14,000 more PSC contractors — here is what changed and what you need to do now

Real take-home figures at £400, £500, £650, and £800 per day — showing the true difference between inside and outside IR35 after all deductions on 220 working days

Mutuality of Obligation is a foundational IR35 test that HMRC deliberately excluded from CEST — here is what it means, why it matters, and how to use it in a dispute

Everything a first-time UK contractor needs to know about IR35 — what it is, what it costs you, who decides your status, and what to check before signing your first contract

IR35 rules 2026 explained in plain English: who decides your status, the April 2026 threshold and umbrella changes, and how to know where you stand.

Is CEST accurate? HMRC's own tool fails to decide around 22% of cases. Here is why CEST says inside IR35 when a tribunal might not.

The PGMOL Supreme Court IR35 ruling weakened a favourite contractor defence. Here is what the 2024 decision changed about mutuality of obligation.

A right of substitution can put you outside IR35, but only if it is real. What Ready Mixed Concrete, Autoclenz and Atholl House actually established.

A salary sacrifice pension inside IR35 can claw back much of the umbrella tax hit. See how it works and model your own numbers across three scenarios.

Seeing employer NI taken from your day rate through an umbrella? Here is the statutory mechanism, why it happens, and whether it is actually legal.

Who decides your IR35 status: your client, your limited company, or HMRC? How the off-payroll rules assign responsibility, and what changed in April 2026.

The Atholl House IR35 case took Kaye Adams nine years to win. Here is what it established about being in business on your own account and why it matters.