We have had a customer that had several counterfeit checks hit their account. We refunded the amount and asked them to use our positive pay product to stop this from happening again. They said they didn't want to use the product. I have heard of a few banks getting their customer to sign a waiver releasing the bank of any liability if it happens again. I find it hard to believe this would hold up in court if the customer actually ended up losing money and decided to pursue it in court. Any thoughts would be greatly appreciated.

This is a question for legal counsel. Safe to say if their were a loss, the customer's attorney would likely argue that the customer didn't understand what they were signing and paint the bank as the big greedy business that strong-armed the customer into signing it.

To answer your other question, if the customer refuses to use positive pay, you have it within your rights to make them an ex-customer.