The identity of a donor can remain confidential if (s)he so requests, if the annual amount contributed is less than 10 minimum salaries.
"(1) Upon receipt of the donation, verification and registration of the donor's identity shall be required, irrespective of its public or confidential nature.
(2) At the written request of the donor, his / her identity remains confidential, provided the donation is within the limit of the annual amount of 10 minimum gross national salaries.
(3) The total amount received by a political party as confidential donations may not exceed the equivalent of 0.006% of the revenue provided in the state budget for that year."
Source: Article 11 (1) - (3), The Law no. 334/2006 on financing the activity of political parties and electoral campaigns, 2006 (as of January 20, 2017)