20. Is there a limit on the amount a candidate can contribute to their own election campaign?

A political entity may raise funds from private sources for election campaign expenditure. Natural and legal persons may give donations in a single calendar year in which elections are held, in addition to donations for regular work, also for election campaign expenditure up to maximum stipulated amount at annual level specified in article 10, paragraphs 1 and 2 hereof, regardless of the number of election campaigns in a calendar year. For financing election campaign expenditure a political entity may also use funds from credits and loans." 
Source; Article 22. Law on financing political activities.

It should be noted that for parliamentary elections, candidates cannot donate directly to their campaign. However, when it comes to presidential elections, candidates can contribute to their own campaigns directly.