Unlike Reg E and Reg DD which only mandate a change in terms notice if the change is to the customer's detriment, Reg CC requires a change any time your funds availability policy changes.
229.18 (e) Changes in policy. A bank shall send a notice to holders of consumer accounts at least 30 days before implementing a change to the bank's availability policy regarding such accounts, except that a change that expedites the availability of funds may be disclosed not later than 30 days after implementation.
Using a statement message would satisfy the requirement provided that all existing customer receive it at least 30 days after the change is made.
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