Core Viewpoint - The article emphasizes the importance of compliance in tax reporting, particularly regarding the declaration of unbilled income and the conditions under which input VAT can be deducted. Group 1: Tax Reporting Compliance - Taxpayers must accurately report unbilled income in the "Sales Situation Detail Table" of the VAT and Additional Tax Declaration Form [4] - For simple business taxpayers, a "confirmation declaration" mode is recommended, allowing for automatic data pre-filling based on tax-related data [6] - If discrepancies arise between pre-filled results and actual data, taxpayers can modify the sales amount and other data before submission [6] Group 2: Input VAT Deduction Conditions - Input VAT deduction eligibility depends on specific conditions, with certain items explicitly excluded from deduction [7] - Excluded items include those related to simplified taxation methods, exempt VAT projects, and personal consumption [7] - Non-normal losses of purchased goods and related services are also not eligible for input VAT deduction [7][8] Group 3: Valid Tax Documents for Input VAT Deduction - Valid documents for input VAT deduction include VAT special invoices, customs import VAT payment certificates, and various transportation service invoices [11] - Only VAT special invoices can be used for input VAT deductions, highlighting the need for proper documentation [10]