What length of time do you recommend in retaining checks for imaging & truncation? I've heard as little as 45 days and as long as 6 months.

While the E-Sign law could affect this, I'd first check state law to see if there is any controlling authority there.

If you find nothing there, look at your process. How long does it take your bank or processor to verify image quality and retrievability? Once you're certain the image is accessible, I'd vote for destruction of the original.

Also, keep in mind UCC Section 4-406(b) which provides that "If the items are not returned to the customer, the person retaining the items shall either retain the items or, if the items are destroyed, maintain the capacity to furnish legible copies of the items until the expiration of seven years after receipt of the items." When you are imaging checks, it's wise to image both the front and the back, in case of a dispute involving an endorsement. If you can't produce a legible copy of the back of the check upon request, I'd question whether you are meeting the 4-406 standard for retention.