When you receive an NSF check, you should notify the customer immediately.

An NSF check isn't always given intentionally, and sometimes it can be for insufficient funds or bank error. For that reason, the customer can be as upset about the situation as you. So, when you contact the client, be respectful, make payment arrangements, give them a date when reimbursement is due, and that's it. Source: The Blueprint, 2021. Photo by Ketut Subiyanto from Pexels.