You are attempting to address two notification requirements. The first is the notice of the impending return, which is required by subsection 229.33(d). That notice need not be in writing (it is to be delivered or given), but it is required to be timely, and should include "the facts" concerning the item being returned. Note that this notice is required whether you are taking no action, placing a hold, or charging the account pending the actual return of the item. By the way, this notice requirement is included not only in section 229.33(d) of Regulation CC, but also in the UCC, at 3-503. Some banks obtain waivers of those notice requirements, particularly if they automatically re-present returned items.
The second requirement is the notice of hold, if you place one. This notice must be written (electronic if the customer has agreed to same in compliance with ESIGN), and it has specific content requirements. The hold is a "reasonable doubt of collectibility exception" hold, and it has to have an expiration date. Generally, that date is either 7 or 11 business days following the day that the check was deposited. When that hold expires and the item has not yet been received (which can happen), you either have to make the funds available, charge the account for the yet-to-be-received return item, or extend the hold (which you can do, IMO, using the last sentence of section 229.13 as your authority: "A longer extension may be reasonable, but the bank has the burden of so establishing."
IMO, placing a hold and providing a hold notice in these situations is risky. It may be a much better policy to simply charge the account when you get a large return notice, suspending the funds pending receipt of the item. It's cleaner, less confusing, and avoids the technical requirements of the section 229.13 hold.
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John S. Burnett
BankersOnline.com
Fighting for Compliance since 1976
Bankers' Threads User #8