4. Is there a ban on corporate donations to candidates?

Political Parties Act 1994, Article 4(1)

Greco Eval III Rep _2009_ 8E Final Hungary 

https://rm.coe.int/CoERMPublicCommonSearchServices/DisplayDCTMContent?documentId=09000016806c6b30

In accordance with the Party Act, the sources of income to a political party are the following: membership fees, subsidies granted from the State budget, pecuniary contributions from legal entities, unincorporated economic associations and private persons, estates of private persons inherited on the basis of their will and business activities of the party (Article 4(1))