27. Are there provisions requiring donations to go through the banking system?

Source: 

Article 6, Law on Political Party Financing  2012 (with 2016 amendments)

Source: 

Article 5, Law on Political Party Financing  2012 (with 2016 amendments)

(BS)

(1) Fizička i pravna lica mogu davati dobrovoljne priloge političkim strankama jednokratno ili više puta tokom kalendarske godine.  (2) Dobrovoljni prilozi u novcu uplaćuju se na transakcijski račun centrale političke stranke.  

Političke stranke dužne su voditi evidenciju o prijemu članarina i dobrovoljnih priloga, te izdavati potvrde o prijemu članarina i dobrovoljnih priloga. Ovlašteno lice u političkoj stranci  uplaćuje članarinu i dobrovoljne priloge neposredno na transakcijski račun političke stranke  najkasnije u roku od deset dana od dana prijema uplate.  

(EN)

(1) Natural persons and legal entities may give contributions to political parties once or several times in a calendar year. (2) The contributions shall be paid to the transaction account of the political party’s headquarters."

Political parties are obliged to keep records of the receipt of membership fees and voluntary contributions, and to issue receipts of membership fees and voluntary contributions. An authorized person in a political party shall pay membership fees and voluntary contributions directly to the political party's transaction account no later than ten days from the date of receipt of the payment.

Avaliable at: https://www.izbori.ba/Documents/documents/ZAKONI/Fin_Stranaka/DOC039-bos.PDF