The article is aimed at determining the order and methodology of auditing the software of the computer accounting system (CAS). It has been found that software auditing should be performed separately for each of its components. The components of the functional part of the CAS software are the database management system (DBMS) and the application software supporting the accountance automation. For auditing of the first component part are used such techniques as general evaluation, subject check of the embedded algorithms of information processing. Auditing the client software algorithms is carried out by means of the control data method, which is reduced to such procedures as creation of another database of test data with imaginary objects and its processing by the client program, as well as introduction in a copy of the real database of imaginary objects (employees, creditors, material values) and the formation of reporting. Not only the current methods of calculation or evaluation of accounting objects, but all of the software, are subject to mandatory verification. This will avoid errors if the enterprise accounting policy changes.