Core Viewpoint - The article discusses the implications of cross-year invoicing practices for corporate tax deductions, highlighting two main scenarios: expenses incurred in one fiscal year but invoiced in the next, and invoices issued in one year but reported in the following year [2][4]. Group 1: Last Year's Expenses Invoiced This Year - Companies can provisionally account for expenses when prepaying quarterly income tax based on the incurred amount. Valid documentation must be provided before the annual tax reconciliation by May 31 of the following year to deduct these expenses without tax adjustments [3]. - If valid documentation is not submitted on time, companies must first adjust their tax liabilities before making retrospective adjustments once compliant documentation is obtained [3]. Group 2: Last Year's Invoices Reported This Year - Companies can retroactively claim deductions for previously incurred but unclaimed expenses by making a special declaration. The retroactive claim period cannot exceed five years [4]. - Any overpaid taxes resulting from these retroactive deductions can be offset against the current year's tax liabilities. If the offset is insufficient, companies may defer the deduction or apply for a tax refund [4]. Group 3: Planning and Documentation - Companies are advised to review unreported expenses and invoices before year-end, notifying relevant departments to ensure timely reimbursement. For expenses where invoices cannot be obtained on time, companies should estimate amounts and make appropriate accounting provisions [6]. - It is essential to retain supporting documentation for expenses without invoices, including contracts, non-cash payment receipts, transportation proofs, and accounting records to ensure traceability of expenses [7].