Depending on the complexity of the audit, the auditor may itemize certain items under review. You should provide all relevant documentation relating to these specific items. If the auditor requests a certain type of documentation, such as an invoice, you should provide that invoice. Otherwise, you should provide all relevant documentation to support your income, deductions, and expenses. Documentation includes records such as canceled checks, invoices, receipts, etc. (Question and answer last reviewed June 24, 2024)