Reference
The accountant's library
Structured practical references that start with a work question, explain the treatment, source and boundary, then lead to a lesson or tool where you apply it.
Internal controls and segregation of duties
A control is not a written procedure but something that stops an error or finds it. The difference between the two is the difference between a business that discovers its own problems and one whose auditor discovers them for it.
Practical output: Work note: Internal controls and segregation of duties — A structured explanation, every official rate with source and review date, then a direct path to a lesson, tool or track.
A decision from the reference: Preventive stops before the fact: holding an invoice from payment until it passes the match, refusing a duplicate invoice number, approval limits by amount. Detective finds after the fact: the supplier statement reconciliation, a review of unusual payments, a surprise count.
Reference boundary: Reviewed on 2026-08-18. Before relying on the treatment, open the linked official source and confirm that it applies to the period facts and the organisation's policy.