A ballot is spoiled where:

1. the ballot is left blank;

2. the ballot is filled in a manner that makes it impossible to determine the voter's decision and the slate/candidate for which/whom such voter cast his/her vote;

3. completing the ballot by casting one's vote for two or more slates or candidates;

4. the voter cast his/her vote on the ballot for candidates from different slates and failed to encircle one of the slates.

With Article 37 of the Act on Amendments to the Act on the Elections of Representatives to the Croatian Parliament (Official Gazette 19/15), which entered into force on 25 February 2015, item 4 was added.