The word "code" appears all over payroll, attached to completely different things. This page is a map of the main code systems so they are not confused with one another - each is its own namespace.
What it means
A code is just a short identifier standing in for something longer. The trap is that payroll's codes are unrelated: an IRP5 source code classifies a type of income, a SIC code classifies an employer's industry, a nature-of-person code classifies who the income recipient is, an employee code is the employer's internal staff number, and a bank branch code routes a payment. Knowing one tells you nothing about the others.
Where it fits in
Each code does its job in a different part of the cycle: source codes structure the IRP5, SIC codes affect ETI and reporting, nature-of-person codes set tax treatment, employee codes identify staff in the payroll, and branch codes get net pay to the right bank. When a document says "code", the first question is always which code.
Key rules
- IRP5 source code: classifies a type of income, deduction or benefit (for example 3601).
- SIC code: the employer's industry classification, relevant to ETI.
- Nature-of-person code: classifies the income recipient (A, C, M, R and others).
- Employee code: the employer's internal staff identifier. Bank branch code: routes the payment.
