A Key Information Document (KID) is a document that an agency or umbrella company must give a contractor before they agree to take an assignment. It is a transparency requirement under the Conduct of Employment Agencies and Employment Businesses Regulations 2003, designed to make sure the worker understands exactly what they will be paid and what will be deducted.
The KID must set out the assignment rate, the deductions that will be taken (including employer National Insurance at 15%, the Apprenticeship Levy and the umbrella's margin), how holiday pay is handled, and the expected take-home pay. In effect it is the audit trail that shows the worker how the headline rate becomes the figure that lands in their bank account.
The KID is one of the firm's practical markers of a compliant umbrella. A clear, honest KID that reconciles the assignment rate down to take-home is a good sign. An umbrella that is vague about deductions, or whose figures imply that statutory costs are not being properly accounted for, should be avoided as a likely disguised-remuneration or skimming scheme. From 6 April 2026 the new umbrella JSL regime gives agencies and end clients a strong incentive to insist on compliant umbrellas, so contractors should expect tighter checks.