What is the supplication to be said when paying Zakat?

There is no specific prescribed supplication for paying Zakat. However, there is no harm in making general supplications like: "Our Lord, accept from us; indeed, You are the All-Hearing, the All-Knowing," provided that this is not taken as a regular practice. It is authentically reported that the Prophet (peace be upon him) supplicated for those who brought their charity, saying: "O Allah, send blessings upon the family of so-and-so."