The tax administration process is carried out by the Tax Administration as the main legislative body authorized to carry out this process. Tax monitoring is a procedure conducted by authorized officers to determine the facts relevant to taxation directly to taxpayers and other persons. Tax audits are performed by tax auditors, tax inspectors and other civil servants authorized for its implementation. The subject of tax assessment may be the verification of one or more tax types in one or more tax periods, checking non-activity-related facts of a business entity and checking the relationship between a company's owner and a company with a company. The level of administrative cooperation and the organization of the underlying supervisory system in different EU member states greatly determines the intensity and efficiency of tax audits in the Union. There are considerable limitations for carrying out such controls where there is a lack of compliance in national surveillance systems. It is therefore essential to have a partial view of tax authorities in the legislation of other member states. For the optimum effect of EU taxation supervision, it is imperative to increase the effectiveness of national monitoring systems, eliminating inefficiencies and addressing cross-border issues with a unambiguous approach. This means that, in relation to the form of tax supervision of any member state they wish to initiate and require the powers of supervision alone, it is necessary to decide in advance whether or not that power is available to the participating (tax authorities) of the member states. In the implementation of tax supervision and in the processing and analysis of tax risks of tax administration of EU member states, different models are used. The most famous are the transactional model and the bulb model. The transaction model of a taxpayer is seen as a set of transactions, while the bullet model implies creating a fiscal chain in which everyone plays an important role in raising the quality of tax returns and achieving a greater degree of tax liability fulfillment. EU regulations regarding tax enforcement in its area should be designed so that different types of surveillance can be distinguished and then associated with the powers necessary to carry out self-monitoring, with increased efficiency. The strategic goal of taxation in the Republic of Croatia is to ensure efficient and cost-effective monitoring of the regularity of the calculation and payment of taxes and other public grants. The selection of taxpayers is based on the risk assessment that is the basis for annual planning. Tax monitoring starts with the delivery of tax audit notice. In case of endangering the purpose of tax supervision, notification must not be provided before the start of 39 supervision. In the process of taxation control, all the important facts that can finally increase or decrease the tax liability are determined. The taxpayer proves the facts in a number of ways: giving information, presenting records, and guiding and presenting business books, business documents and other documents. The tax inspector may request the necessary information from employees and third parties without a special written request. Business books are very important for the implementation of tax supervision because they are the basis for determining the facts relevant to taxation. Business books are kept based on regulations regulating a particular type of tax. The tax base of natural persons is estimated as the difference between the receipts and expenses of a taxpayer for private purposes and / or acquired private property and reported income or profits, unless such difference can be proved to be taxed. The concluding discussion is carried out before the drafting of the minutes, discussing the controversial facts, legal assessments are made and conclusions and their impact on the determination of the tax liability are established. Fundamental acts in tax supervision are: conclusion in tax control, tax audit record and tax control. An appeal to the tax administration can be submitted to the Ministry of Finance through the organizational unit of the Tax Administration that issued the ruling. The renewal of the procedure is an extraordinary remedy that can be initiated when the tax supervision is completed by a decision against which there is no regular remedy (appeals). Administrative disputes are solved by the Administrative Court and the High Administrative Court of the Republic of Croatia. The administrative dispute is initiated by a lawsuit. The administrative dispute may be initiated against the decision of the second instance and against the first-instance ruling and the conclusion against which no appeal may be lodged in the tax inspection. A tax violation is a violation of tax regulations that is prescribed by the Law on Tax Administration, General Tax Law and special laws on certain types of taxes and contributions. It is prescribed for him to impose fines. The tax secretory includes the information that the taxpayer provides in the tax audit, as well as any other tax-related information. A taxpayer may request the exemption of inspectors in tax supervision, and the exemption of the tax inspector shall be decided by the head of the organizational unit of the Tax Administration which performs tax supervision and the exclusion decision. To the exclusion decision no appeal can be lodged, but it can be appealed against the ruling on tax supervision. A taxpayer in tax supervision may be represented by a proxy, a tax adviser, a legal representative and a businessman of affiliated persons, and a representative ex officio.