African Union Convention on Preventing and Combating Corruption (Adopted in Maputo on 11 July 2003) http://www.africa-union.org/home/Welcome.htm

This is the only regional or international convention with mandatory reporting requirements for political parties. Article 10 states that "Each State Party shall adopt legislative and other measures to: (a) Proscribe the use of funds acquired through illegal and corrupt practices to finance political parties; and (b) Incorporate the principle of transparency into funding of political parties."

Canada's Electoral Commission
http://www.elections.ca/

Elections Canada is an example of an electoral commission with a user-friendly system of publishing financial reports. It contains searchable databases with candidates and political parties, their electoral expenses and the regulations concerning them. Information includes contributions and expenses at federal elections and by-elections; candidates' financial reports; contributions and expenses; and third parties' financial.

Council of Europe, Recommendation (2003)4 of the Committee of Ministers to member states on common rules against corruption in the funding of political parties and electoral campaigns
(Adopted by the CoE Committee of Ministers on 8 April 2003)
http://portal.coe.ge/downloads/REC%20(2003)4.en.pdf

This is the first international instrument to provide detailed recommendations on what a party finance regime should look like. The recommendations focus heavily on sources of funding - supporting a system that balances private and public financing - and on the merits of disclosure. The treatment of enforcement and monitoring is, however, less extensive.