The UCC allows the effect of its provisions to be altered by agreement of the parties, but not the obligations of good faith, diligence, reasonableness, and care. UCC 1-302
A bank might, as a customer service, agree to make its customers' stop payment orders valid for a year, and it's unlikely that a customer would object, since that would tend to prevent disreputable payees from "sitting" on a check until a stop order expires, trying to sneak it in when the customer's guard is down. The only person with a reason to complain would be the payee on the check or other item, and he/she/it has no legal recourse against you for honoring the stop after the normal 6-month period.
A depositor might have a legitimate beef with your bank if you decided to shorten the term of a stop to 3 months, since the law clearly says the right exists for 6 months. It might be difficult for the bank to argue that the consumer knowingly agreed to such a change.
The only other person who might have a gripe if you doubled the longevity of stop orders is whoever pays your IT bill. Your outside servicer (if you have one) might exact a per-stop record fee, and extending stops to one year's life would increase your costs. If your processing is in-house, the costs is measured in storage costs and processing time.
Oh, one more thought -- your stop report and stop suspects report will grow in length and take more time to be attended to.
_________________________
John S. Burnett
BankersOnline.com
Fighting for Compliance since 1976
Bankers' Threads User #8