The regulatory guidance has only focused on what banks do with/to consumer accounts. Businesses are believed to have more bargaining power and a better grasp of pricing practices, apparently. In any event, businesses don't cast ballots in November (he says cynically).
If there is anything that would address business account NSF fees, it's at a state level.
Whether or not you have a notification requirement for business accounts and how many days are required are matters of contract, unless by some rare chance they are addressed in state laws.
_________________________
John S. Burnett
BankersOnline.com
Fighting for Compliance since 1976
Bankers' Threads User #8