This phrase is commonly written on the signature strip of a credit card in the hopes that by doing so, the holder of said card is somehow protected from unauthorized purchases in the event their card is stolen. It really makes sense that when you buy something with a credit card, you should have to show some sort of identification, or should at least have the option of that being a requirement for your own peace of mind. I mean, you have to show your ID to pay by check, right? Why should this be any different? There are some obvious reasons. In general, when you lose money from your bank account due to theft or fraud, there's very little recourse in terms of getting that money back. You're generally screwed. If someone gets your debit card and goes to town with it, you're much less likely to be protected than if the same thief used a regular credit card. Of course, credit / debit cards have a ton of convenience associated with them, which is why you see commercials on TV hailing the benefits of having a check card because you "don't have to show ID." I always found it peculiar that the notion of having a piece of plastic that allows immediate withdrawal from your bank account without any identity verification is somehow a good thing.
It makes sense that if you want to go through the inconvenience of showing your ID every time you make a purchase, you should have that option. For this reason I always write "See Photo ID" on my credit cards. I've never had any problem with it, but I have pondered how much it really can protect one's self. Let's say your credit card gets stolen and a bunch of charges get rung up. Your credit card company is giving you a lot of hassle as far as dropping the unauthorized charges, so you tell them "well, I wrote 'See Photo ID' on it, so really the merchant should be at fault." Assuming your credit card is never recovered, which is likely, how do you prove that it really said "See Photo ID?" During this thought experiment of sorts I found myself imagining the act of going around to all of the merchants I've used my card at, asking them to testify to some credit card authority that my card did in fact say "See Photo ID," sparing me of all responsibility. And assuming you currently "sign" your cards in this manner, what is the relative frequency at which your ID is actually checked? For me, it's maybe 10% of my purchases.
Though I'd had my nagging doubts I still figured it was a good idea, and continued to do it whenever I received renewed cards. Today's events, however, have shed more light on the subject and have forced me into learning more about the pros and cons of "signing" your cards in this fashion.
I was headed to the Post Office to mail off a package to an eBay customer, and planned on using my Mastercard to pay for the postage. Upon giving the cashier my credit card, she politely informed me that "Generally, we can't accept this because on your card it says 'Not valid unless signed.' Since the card itself is not signed, it's not valid. The card companies make the rules, not us, but I'll go ahead and take it today. Some credit card companies don't put this on the cards, however, so you can write 'See Photo ID' on their cards." She'd apparently dealt with this many times before and had a spiel all ready to go, the kind that has just about everything wrapped up into a convenient little ball that brutally shatters all "buts" to pieces before they even manifest themself into some sort of audible speech. Besides, she was taking the card anyway, so I didn't care too much. I thanked her for accepting it and informed her that it seemed "ridiculous" that credit card companies would forbid this practice. She agreed and I left, hell-bent on proving her and apparently the entire US Postal Service wrong. In retrospect I was kind of miffed for a moment; "if you're going to accept it, just accept it and don't give me no lip." On the other hand, I realized she was warning me that others at the Post Office might not treat me so kindly, the way a bartender tells you "everyone else charges $6.75 for a Long Island" compared to their $4.50 in the hopes that you'll tip 'em more, except there's no tip in this case and so my whole analogy just withers and dies.
I knew they had to be wrong, I mean, it made no sense that they would prohibit this, right? I figured "Not valid without signature" meant "Not valid without signature or some written text referring to another official ID with an authorized signature on it," but "they" figured that was implied, duh, and weren't going to waste a bunch of space writing that, of course. Unfortunately for my ego, Google humbled me within minutes. I searched for "credit card 'See Photo ID'" and found a few links recommending the practice, but also discovered this one:
http://www.creditcardgoodies.com/grapevine/page23.php
Upon doing a "Find" for "See Photo ID" within the text of the page, I found a rather poorly written paragraph explaining that VISA and Mastercard prohibit this practice, and in fact if you do sign your card with your actual signature, Mastercard merchants are forbidden from even asking you for ID. And if they do ask you, you can call 1-800-MC-ASSIST to narc them out. I didn't bother to find more to substantiate the second claim, but I did find this link:
http://www.usa.visa.com/business/merchants/fraud_basics_cardpresent.html#link4
...Which is VISA's official page explicating various procedures in determing whether a card is being used fraudulently. They address this particular issue and state flat out that "See ID" or "See Photo ID" is unacceptable and that as a merchant you are to force the customer to sign the card over the text unless they'd rather not purchase the product they intended to.
Upon second thought this makes sense. Considering these card companies have absolutely no way of knowing whether or not you really wrote "See Photo ID," they would be opening themselves up to whole new avenues of fraud by allowing such practices. And haven't you noticed how often your credit card company will hound you with telemarketers, begging you to buy new "anti-identity theft" protection and other forms of expensive insurance. Why would they want people to assume that, by writing "See Photo ID," they have somehow fully absolved themself of all responsibility in the event their card is jacked? Besides, it's perfectly possible to ring up $10,000 in purchases without making a single "in-person" transaction, rendering it impossible to even check for ID. To fully implement this, they would need to put a verification system into place where card holders demonstrate in some tangible, provable way that they have in fact put "See Photo ID" on their card and will not consider any purchase "authorized" unless an ID was checked. Then, the merchant would need to somehow verify that they did check for ID, which is otherwise not a standard practice unless the merchant happens to be particularly untrustworthy of credit card users, as porn and head shops are particularly prone to be...not that I'd know. And of course purchases done over the phone and internet would be prohibited for "See Photo ID" participants because it would render everything else pointless. This is all too impractical for "them," as they'd basically need to charge people to provide this service while creating more hassle and inconsistency for their merchants. And since people who write "See Photo ID" have enough of a false sense of security to where they don't feel they need to pay for costly, monthly-rate special insurance, they are unlikely to be content with paying for the privilege of writing this on their cards.
Assuming the second claim on the first link is true, untrustworthy vendors who ask you for ID upon showing them a signed Mastercard are just as much in violation of MC policy as a vendor who allows a "See Photo ID" card to be used. This means that when I'm buying some porn at Fascinations and they demand my ID, I could technically refuse and call the number right there to prove it to them...but that's an issue for a different writeup entirely. I'm too damned lazy to actually call the number at this moment.
There you have it. As to the postal cashier's claim that certain card companies don't have rules prohibiting this, I have not substantiated those either. What I do know for a fact is that VISA apparently does prohibit this practice and in theory all merchants who accept cards with "See Photo ID" on them are breaking the rules. It stands to reason that Mastercard has a similar policy, although I did not find a corresponding page for them.
What this ultimately means is that in the event that you are in fact hassled by someone for writing this commandment on your card, you know better than to make an ass of yourself arguing about it (like I might've if she'd rejected my card, if there hadn't been a line behind me) and also know that you have the option of signing over the "See Photo ID" text on the strip if you really need to use that card right now.