A traditional AMEX card will still show up as opening a credit line and will count as a credit inquiry in terms of your recent inquiry history. That said, because you are paying the bill monthly it is not a revolving line of credit and as many Amex cards don't have limits, your overall credit limit doesn't go up. Whether or not this is good or bad for your score depends greatly on your current credit situation and history. For example, if you have a lot of credit card debit versus your total credit ratio, this won't help lower that ratio and thus it won't help with that factor but it may help by giving you another line and opportunity to build history.