What are the requirements on these accounts when the minor turns 18? Do you allow the minor to take over the account as long as the custodian is present to change the account or do you make them open an entirely new account in just their name (unless they ask that the parent remain on the account)? We are re-evaluating how to handle these accounts so a different insight would be great
Thanks!!

Whether you (a) create a new account or (b) file maintenance the existing account seems to depend on your CIP and what the custodian wants. Personally, we would open a new account. But, we won't take names off of accounts generally. That is, for name removal, the customer must close the account and open a new one.

It appears others have already responded to similar questions:

http://www.bankersonline.com/forum/ubbthreads.php?ubb=showflat&Number=603191

http://www.bankersonline.com/forum/ubbthreads.php?ubb=showflat&Number=63811

I believe the answer relies on this:

(760 ILCS 20/21) (from Ch. 110 1/2, par. 271)
Sec. 21. Termination of Custodianship. (a) The custodian shall transfer in an appropriate manner the custodial property (to the extent that it has not been used pursuant to this Act) to the minor or to the minor's estate upon the earlier of:
(1) the minor's attainment of 21 years of age with respect to custodial property transferred under Section 5 or 6;
(2) the minor's attainment of majority under the laws of this State other than this Act with respect to custodial property transferred under Section 7 or 8; or
(3) the minor's death.
(b) To the extent the custodial property is real property or an interest in real property, no conveyance or delivery to the minor or to the minor's estate is necessary to terminate the powers or rights of the custodian upon the minor's attainment of age 21 or 18 years, as the case may be, or upon the minor's death.
(Source: P.A. 84‑1129.)