credit card signature is all the id neededwhen you pay for merchandise with a visa card, mastercard, or american express any store that accepts these cards should accept yours too, no questions asked. it's part of the deal that merchants agree to when they become participating members.they must check your signature and the card - electronically or by telephone - to be sure it's valid. once the answer comes up yes, they can go ahead and charge. they can't ask you for any further identification - not a license plate number, social security number, proof of address, phone number or photo id.your personal id isn't needed because visa, mastercard, and american express all guarantee payment on cards that have been properly checked. if the issuer mistakenly authorizes a sale on a bad card, it should make good. mastercard says that merchants receive instant settlement. the contract mastercard merchants sign specifically prevents them from asking for personal id.unfortunately, not all merchants play by the rules. some, apparently, haven't read them.what you can domastercard wants to hear about merchants who break their rules. send the name and address and an account of what happened to mastercard worldwide 2000 purchase st. purchase, ny 10577 or call 1-800-300-3069. the merchant's bank will get a stiff letter, ordering it to investigate and bring the offending store into line - or pay a $2,000 fine. you may also report violations online:http://www.mastercar...violations.htmlvisa enforces the same rules as mastercard. "when we hear about a violation, we ask the bank that signed the merchant to get together with the merchant and see that the practice is stopped," visa representative states. to report a merchant, send a letter to the bank that that issued your visa card or call 1-800-visa-911.american express also prohibits merchants from asking for ids. "all a merchant is supposed to do is take an imprint, make sure the signature matches and swipe the card through the terminal, to get authorization."