55. Which institution(s) receives financial reports from political parties and/or candidates?

Swiss Confederatio Federal Assembly Elections ODIHR Needs Assessment Mission Report, 22 October 2023
(the law only stipulates that "the Federal Council shall designate the competent authority for verification and publication")
Article 76g Federal Act on Political Rights (Bundesgesetz über die politischen Rechte)
[Art. 76g Zuständige Stelle
Der Bundesrat bezeichnet die Behörde, welche für die Kontrolle und Veröffentlichung zuständig ist.]

Swiss Federal Audit Office.