Which one of the following principles of accounting would you be violating if you used FIFO one year, then switched to LIFO and then back to FIFO? a) Materiality Principle b) Conservatism Principle c) Matching Principle d) Consistency Principle e) Inventory Valuation Principle. The perpetual inventory system normally does not use which of the following as a formal account in the general ledger. a) Purchases Returns and Allowances account. b) Sales Returns and Allowances account. c) Accounts Receivable control account. d) Sales account e) All of the above are used by a company that maintains perpetual inventory