We will be raising the ATM cash withdrawal limit to $500 and our atm debit card limit to $2500. We will change the Terms and Conditions disclosure for new customers. However, is notice to existing customers required? Where in the Reg. can I find the answers to this?

We are just going through this as well. Look in Reg E and see if you meet the criteria for a 21 day prenotice. We sent out statement stuffers to our customers stating the change and then also followed up with a letter to make sure they understood the changes prior to making the change. We were going from a daily dollar limit to a positive file submission with a new ceiling. I changed our current Reg E disclosure to reflect the new limits.

You won't find it. However, there are stories, perhaps apocryphal, that a customer whose limit is increased and somehow got clobbered with a bunch of unauthorized transfers claimed that he wasn't responsible -- even after several months' worth posted -- based on the fact he thought his limit was $500, not $2,500.

Some customers may not want their limits set that high. Notifying them -- by statement message if you want -- gives them a chance to ask for a lower limit.

I think it's something you should do, even if you don't have to.