Since the inspection of financial books is the main means of customs audit, the following will focus on this method. The methods of financial book inspection are divided into forward inspection method and reverse inspection method according to the different bookkeeping order of the accounting data; there are verification method and review method according to the technical content of the accounting data; there are detailed inspection method and random inspection method according to the size of the scope of the accounting data.
(1) Forward inspection method and reverse inspection method
① Forward inspection method. Forward inspection is to start from the accounting voucher in the same direction of the accounting bookkeeping order and gradually trace to the accounting books and accounting statements. The forward inspection method has the following characteristics: first, it starts from the original record of the economic business, starting from small things and going from point to surface; second, it focuses on the mechanical verification of the books and documents; third, the forward inspection method focuses on determining the authenticity and legality of the business activities of the audited person through the review of the original vouchers. Its disadvantages are that it does not focus on the big picture, cannot grasp the key points of the audit, and has low audit efficiency. Since most accounting documents are numbered and bound in chronological order, it is not convenient to conduct in-depth and systematic review and research on various types of business by business category, which is not conducive to the division of labor and cooperation among auditors.
② Reverse check method. That is, in the opposite direction of the accounting order, the person who reports the documents will reveal the weak links and abnormal phenomena in the business activities of the audited person, find clues, clarify the key points, and then trace the general ledger accounts and their detailed ledgers, and then check the accounting documents, review the original documents, and find out the reasons and facts. It can understand the basic situation of the company’s production and operation as a whole, quickly find problems, focus on the audit, and improve the efficiency of the audit. At the same time, the reverse check method can systematically check accounts by business and subject, which is convenient for the division of labor and responsibility of auditors.
(2) Verification method and review method
① Verification method. Verification includes two meanings: review and cross-check. Review refers to the re-verification, verification and verification of past accounting records. Cross-checking refers to checking the same figures reflected in two or more aspects of past accounting records to find out the balance between various accounting materials, so as to find out the gaps, expose errors and frauds, and verify the authenticity of the operating results and financial status reflected in the accounting statements. In actual work, it is usually checked between vouchers, between vouchers and account books, between account books, and between account books and accounting statements.
② Review method. Review refers to the detailed review and study of accounting vouchers, account books, statements and related materials, so as to preliminarily determine whether there are any problems with the operating activities reflected in the vouchers and statements, find any suspicious points, and then determine the focus and direction of in-depth inspection.
(3) Detailed inspection method and random inspection method
① Detailed inspection method. It refers to a method of grasping the authenticity and legality of the operating conditions of the audited person by conducting a thorough and detailed review of all accounting materials of the audited person during a certain audit period.
② Random inspection method. It refers to a method of selecting some accounting data from the audited unit during a certain audit period for inspection, and using this to infer the authenticity and legality of part or all of the audited person’s operating conditions. To use the random inspection method for auditing, auditors must seriously consider the following three issues: the items to be inspected, the number of random inspections, and how to draw conclusions based on the random inspections.