Helpful Tip: Unsigned Credit Cards
Newspaper and magazine articles, including those written by consumer advocates, sometimes give cardholders the impression that not signing their cards protects them from fraud.
As a result, cardholders are presenting unsigned cards or cards with the notation "See ID" written on the signature panel. Unsigned cards or those with "See ID" written on the signature panel are invalid according to Visa and MasterCard Operating Regulations. Merchants or acquirers should not accept unsigned cards.
So the next time you get a new or reissued card, be sure to sign it immediately. That way, you can avoid the inconvenience of having your card rejected.