Why do some credit cards display the 4 last digits of the credit card in the signature blank next to the CVV code?
For example, I noticed that my newly issued Bank of America Travel Rewards card now display the 4 last digits of the next to the CVV code, whereas the old one didn't have it.
In the example below, you can see the 4 last digits of the credit card (3456) next to the CCV code (123):
Cards that include the last 4 of the PAN in the signature strip typically also include multi-colored watermark text or images under the numbers, which are printed in black. This acts as a fraud deterrent, since a scammer who melted down the embossed numbers and re-embossed new numbers would also have to change the number without destroying the watermark.
Documentation from card networks about card features (which I have offline at my employer) mentions that merchants should validate the digits when they're checking the signature against the customer's ID. Of course, merchants rarely check signatures, so it's unlikely that this number check is ever actually implemented.
With the advent of chip cards, physical security features are quickly becoming less important, as is evidenced by some newer cards which don't even use embossed numbers, or which feature designs where the number is printed on the back or in other atypical locations.
I'm just guessing here, but perhaps the simplest explanation is the right one: It's supposed to prevent you from gluing a card of your own (with your signature on the back) to a stolen card (with someone else's data and chip on the front), so as to use such a stolen card for chip-and-signature transactions.
