The controls are usually connected with the information systems and the accounting. The accountants should be interested in the verification of accounting data and their security. The verification of correspondence of accounts and the account classification, the controls of the objective and formal accuracy of the accounting and tax documents, the controls of the journal and the general ledger, the controls of the synthetic and analytical accounts, the verification of unusual accounting transactions, the controls of the accrued costs and deferred revenues and the controls of the complete accounting ahead of time for making return should be matter of course for the accountants. Likewise they should verify the parameters of the accounting system such as the current rate of value added tax, the rate of social and health insurance, the depreciation rate or information on the accounting entity. The most vital verification is the continuous control of the accounting data. At the same time the paper describes the recommendations in the accounting data security: the rules for the password handling, the rules for the data backup, the rules for the closing of applications, the rules for the electronic mail, the rules for Internet and the rules for the physical security of data. The rules mentioned above and the controls described in this paper can assist the accountants to better secure their accounting data. The main purpose of this paper is to familiarize the readers with the significance of information security in the accounting, the application of controls in the accounting information systems and to offer the recommendations for accountants using accounting data for the day-to-day exercitation. Likewise, it is intended for everybody who wants to secure his or her data.