At minimum, clinics need: complete monthly financial statements (P&L, balance sheet, cash flow), bank reconciliation records, payroll registers with tax remittance documentation, depreciation schedules for medical equipment, and a clear separation of clinical income from other income streams. For audits or partnership buyouts, you'll also need 3–5 years of clean, consistent records showing income by service type. A bookkeeper ensures these are maintained continuously — not scrambled together when a notice arrives.