The Zambia Revenue Authority (ZRA), like most modern tax administrations, administers taxes on self-assessment principles, as opposed to administrative assessment. The self-assessments system is where, at the end of an accounting period, taxpayers are allowed to calculate their own taxable income and tax liabilities and make a declaration to ZRA on tax returns and also make the payments for the declared liability by the prescribed due dates. This has cost and efficiency advantages over the administrative assessment system, where taxpayers have to hold on to their payments until a tax official makes an assessment.
The disadvantage of the self-assessment system is the reliance on voluntary compliance. This tends to gradually reduce over time if not properly managed. To manage this risk, tax administrations design, among other compliance management programs, audit programs where some taxpayers are selected for audit. This page explains the audit requirements for taxpayers in order to ensure that they do not become costly and an inconvenience to their businesses.