Audit shall be carried out by audit firms in which 3/4 of the voting rights are held by EU/EEA audit firms or EU/EEA-certified auditors. The majority of the members of the management board and the president of the board must be EU/EEA certified auditors. If the management board consists of only two members, one of them must be an EU/EEA-certified auditor. Audit firms from third countries may provide audit services in Croatia based on the principle of reciprocity between the Republic of Croatia and third countries.
A certified auditor may, however, be a citizen of the Republic of Croatia or a foreign citizen. An EU auditor or a third-country auditor has to be formally recognized and approved by the Chamber as statutory auditor. The foreign professional qualifications of an EU auditor or a third-country auditor shall be formally recognized and approved after the tasting of candidate’s knowledge of the legislation of the Republic of Croatia, required for carrying out audits. 
The issuance of a work permit to a certified auditor from a third country, however, is subject to reciprocity.
"CHAPTER I - SUBJECT PROVISIONS
Article 4. Concepts
Some terms for the purposes of this Act have the following meaning: […]
6. an auditing company is a legal person established in the Republic of Croatia established as a company in one of the legal forms in accordance with the law governing the companies and which has a work permit issued by the Ministry of Finance in accordance with the provisions of this Act. [...]
8. an audit firm from another Member State is a legal person and / or other entity irrespective of its legal form from another Member State having an authorization from the competent authority of that other Member State to perform auditing serviecs and is registered by the Ministry of Finance in accordance with the provisions of this Act. [...]
11. Registration is the procedure for certifying the auditing company from another Member State, a third country auditor and an auditor in a third country that is carried out by the Ministry of Finance in accordance with the provisions of this Act.
12. the entity performing the audit in a third country is a subject, regardless of its legal form which, on the basis of an authorization issued in a third country, carries out an audit of the annual financial statements or annual consolidated financial statements of a company headquartered in a third country other than the entity registered in on the basis of an authorization to work as an audit firm in a Member State in accordance with the rules of that Member State. [...]
28. Member States are Member States of the European Union or States party to the Agreement on the European Economic Area.
29. The third country is a non-member country.
30. the parent Member State is a Member State in which an authorized auditor or audit firm has been granted a work permit in accordance with the rules of that Member State.
31. the host Member State is the host Member State in which the authorized auditor who holds the work permit in the home Member State has been granted a work permit or in which the audit firm which holds a work permit in the home Member State is registered in accordance with the rules of that Member State host.
[...]
Article 5. Persons authorized to carry out auditing services
(1) Audit services in the Republic of Croatia shall be carried out by an audit firm approved by the Ministry of Finance. The auditing firm must have at least one authorized auditor.
(2) A statutory audit in the Republic of Croatia other than the auditing company referred to in paragraph 1 of this Article shall be carried out by an audit firm from another Member State which is registered by the Ministry of Finance.
[...]
CHAPTER II - APPROVAL OF EMPLOYED AUDITORS AND AUDITORS
Article 7.Authorization to work for an authorized auditor
(1) The Ministry of Finance will issue a work permit for auditing services to a natural person who meets the following conditions:
1. has passed the audit exam and
2. has a good reputation.
(2) The work permit is a public document.
(3) The Ministry of Finance will decide on the application for the work permit within 30 days from the date of receipt of the formal application.
(4) If the applicant for the issuance of a work permit does not remove the deficiencies of the application in accordance with the conclusion within the deadline set by the Ministry of Finance, and the application cannot be acted upon, the Ministry of Finance will reject the application by decision.
(5) After the work permit is issued, a natural person acquires the title of authorized auditor.
[...]
Article 17. Authorization to work for an auditing company
(1) The auditing company shall be established as a company in accordance with the provisions of this Act and the laws regulating the companies.
(2) The Ministry of Finance shall issue a provisional decision on the approval of work for performing auditing services to the audit firm that meets the following conditions:
1. Three-quarters of the voting rights are held by audit firms, ie authorized auditors or audit firms, or authorized auditors from another Member State
2. Most and up to three-quarters of the members of the Management Board or the Management Board are authorized auditors or authorized auditors from another Member State, and when the Management Board or the Management Board has no more than two members, at least one member must meet this requirement
3. Has a good reputation from Article 10 of this Act
4. Natural and legal persons, founders of the company and their real owners, as defined by the law regulating the prevention of money laundering and terrorist financing, have a good reputation in Article 10 of this Act in the case of newly established companies.
(3) At least one member of the board of directors or the board of directors of the audit firm must actively serve the Croatian language.
[...]
CHAPTER IV - AUTHORIZATION TO WORK FOR AN AUTHORIZED AUDITOR FROM A THIRD COUNTRY AND REGISTRATION OF AN AUDITOR IN A THIRD COUNTRY AND AN ENTITY FOR PERFORMING AN AUDIT IN A THIRD COUNTRY
Article 27. Authorization to work for an authorized auditor from a third country
(1) On the basis of reciprocity, the Ministry of Finance can issue a work permit for the performance of a statutory audit to a natural person from a third country to whom the work permit was issued by the competent authority of the third country if he submitted a request with proof of fulfillment of conditions equivalent to those established in Articles 7, 10 and 11 of this Act and if he passes the competency test from Article 23 of this Act.
[...]
Article 29. Registration of an auditor in a third country and an entity to perform an audit in a third country
(1) Under the terms of Article 30 of this Act, the Ministry of Finance shall, at its request, register an auditor in a third country, or an entity for auditing in a third country, if it issues an audit report on annual financial statements or annual consolidated financial statements of an issuer that has its registered office outside the European Union, whose transferable securities are listed on the regulated market in the Republic of Croatia in accordance with the law regulating the capital market, except in the case of issuers of debt securities that are still in circulation and to which one of the following applies:
[...]
Article 30. Conditions for registration of an entity to perform an audit in a third country
(1) The Ministry of Finance will register an audit entity in a third country if the following conditions are met:
1. the majority of the members of the management or board of directors of the entity for auditing in a third country meet the requirements that are equivalent to those from Articles 7, 10 and 11 of this Act
2. an auditor in a third country who performs an audit on behalf of an audit entity in a third country meets the requirements that are equivalent to those from Articles 7, 10 and 11 of this Act
3. audits of annual financial statements or annual consolidated financial statements referred to in Article 29, paragraph 1 of this Act are performed in accordance with International Auditing Standards, International Guidelines for Auditing Practice, International Standards for Insight Engagements, Other Assurance Engagements, i.e. for related services, and International quality control standards if the specified standards and guidelines have been adopted by the International Auditing and Assurance Standards Board (IAASB), or are prescribed by European Union law, and requirements from Articles 48, 49, 52 and 62 of this Act, or equivalent standards and requirements
[...]" (AUDIT LAW NN 127/17 [google translated])
AUDIT LAW NN 127/17 [google translated])
[<a href="https://narodne-novine.nn.hr/clanci/sluzbeni/2017_12_127_2873.html">Law</a>]