Does anyone know if there is an actual timeframe for mailing back the opt-in confirmation to the customer. I read the commentary and did not see anything, but I could have missed it. Thanks

7. Written confirmation. A financial institution may comply with the requirement in § 205.17(b)(1)(iv) by providing to the consumer a copy of the consumer’s completed opt-in form or by sending a letter or notice to the consumer acknowledging that the consumer has elected to opt into the institution’s service. The written confirmation notice must include a statement informing the consumer of his or her right to revoke the opt-in at any time. To the extent the institution complies with the written confirmation requirement by providing a copy of the completed opt-in form, the institution may include the statement about revocation on the initial opt-in notice.

The proposed clarifying amendments to Reg E would add to that the following:
There is no specific time frame, but until you send it, you cannot impose overdraft fees for card transactions subject to §205.17.

That is what I thought - thank you for confirming:-)