It used to be very common to see something like "absence of endorsement guaranteed" on the back of checks that were processed in lock-box operations -- typically contractual payment handling businesses that specialized in processing accounts receivable checks for businesses and depositing them to their bank accounts for them. Sometimes these operations are provided by banks themselves.|
The stamp used to mean that "even though the payee hasn't endorsed this check, we guarantee that the check is being deposited to the payee's account." Some changes in the Uniform Commercial Code (specifically section 4-205) put that guarantee into the law, so the stamp is no longer significant.
Published on BankingQuestions.com 10/23/06