Due to the rapid and continuous development of technology and the fact that many organizations are trying to digitize their operations, there is a need for increased use of methods for document protection. However, documents in physical form, such as bookkeeping documents, are still a very important part of any business and therefore it is necessary to ensure their proper and functional protection, because just one wrong document can put the business of a company at risk. We are witnessing very dangerous hacker attacks on large systems such as banks, insurance companies and hospital systems therefore it is still necessary to have key documents in print and protected form. The main purpose of this thesis was to show what bookkeeping is and what its role is in a company, to give an overview of the division of business documents and to explain each group in more detail, and to explain what document protection is. Along with the protection of documents comes the sanctions that follow the one who falsifies a document, and what is common to every sanction that is prescribed for the falsification of a certain document is that each one is in the form of a prison sentence, only for a different duration. The advantages of digitalization of documents in relation to the use of physical documents were also mentioned, but like everything else, digitalization of documents has its disadvantages that need to be considered before digitizing the business of a company. New methods of document protection that are used on physical documents are also presented, and although the examples are given based on personal documents, some of these methods can also be used on bookkeeping documents.