Scenario:
Customer has 1 year CD and wants to change to a 2 year CD. Does your institution issue a brand new signature card and account number with 2 year disclosures... OR... keep the same account number and signature card but just issue new 2 year disclosures?

Will you just alter the terms on an existing CD like that, or are you closing one account and opening the other? Sounds like a new account relationship, but that's purely opinion based on no understanding of how bank account structures work. For most CUs, the signature card wouldn't at all be impacted and the CD is a separate contract that exists under the pre-existing member number.

If the CD had matured, we would keep the same account number and have them sign a maintenance form and issue new disclosures.

Thanks for your response.
Just wondering what a maintenance form is?
We are a bank so our set up is not like a credit union where each member has a unique number.

We close and reopen. It just keeps everything cleaner and we have a good paper trail.

Since the term is changing, we close and reopen.

Because you are changing the terms of the orginal "contract" I would close and reissue a new one.

This debate could go on forever on what you might or might not do at your specific institution and absolutely none of it is at all relevant to the original question.

They need to be asking their legal counsel as without reviewing the document in which they entitled "signature card" nobody has any idea what it is. Is it a depositor's contract? Does it only cover one account or the entire account relationship of the customer? Does it just provide the bank with a signature specimen? Does the bank use a master CD contract with only receipts for the individual CDs that are opened? Etc., etc., etc......