Note however that this only applies to political donations:
Corruption is not a significant problem in Finland. A 2010 law requires candidates and parties to report campaign donations of more than EUR 800 ($1,072) in local elections or EUR 1,500 ($2,010) in parliamentary elections. However, the campaign law had no major impact on campaign financing for the 2011 elections. Finland was ranked 2 out of 183 countries surveyed in Transparency International’s 2011 Corruption Perceptions Index.
Source:
http://freedomhouse.org/report/freedom-world/2012/finlandI'm not sure why this fact was left out of the article. So basically, if you happen to own a cancer research lab or a homeless shelter or anything else that isn't a political party, then you should be OK.