Overview of audits by IRAS

Key requirements

IRAS checks supply classification, output and input tax, completeness and the transaction-to-return trail through correspondence, interviews or visits. Sales and purchases listings require invoice dates and numbers, counterparties, descriptions, pre-tax amounts and GST; purchases also identify supplier GST numbers, while goods destinations can be relevant for sales. Keep invoices, export evidence and self-review checklists available and explain the accounting process. Officers carry authority identification, and IRAS can seek confirmation from suppliers, customers and banks. Provide timely, complete replies and access to relevant records. Most audits finish within 12 months, depending on complexity and cooperation, and the written outcome explains adjustments and penalties. An objection is available through its separate procedure. Periodic reconciliations and voluntary correction help address errors before discovery.