Tonnage tax compliance requires audit certification of net tonnage, charter in limits and tonnage income computations. Audit report template for the tonnage tax regime requires the auditor to verify separate books for qualifying ship operations, compute ship level and total tonnage income (owned or chartered), certify compliance with the 49% charter in net tonnage limit, detail related party transactions, compute depreciation for qualifying assets under scheme rules, certify tonnage tax reserve creation and utilization, and apply prescribed TEU/volume/weight conversion formulas to derive deemed net tonnage for income computation.