<prompt> Human: Thinking about opening a Costco Citi Bank Credit card. A lady I work with opened one with a credit score of around 620, and was approved for 4000 credit. Does anyone know what the credit score requirement iscredit line you can receive? Or if this Costco option is legitimate?My other option is to ask chase to raise my current credit limit from 500 to whatever theyll give me. My credit score is 658 and its clean with no collections. Only nag is one missed payment from a previous card card payment. Thanks a bunch  <response>: I have the Costco Citi card, and use it as my primary credit card for almost all purchases. I do most grocery shopping at Costco, get all my gas at Costco, and plenty of other shopping there too. Plus I use the card for non Costco purchases as well. Its the highest cash back card Ive seen for the way I spend money. Ive got 450 Costco cash rewards built up so far this year, so it easily offset the cost of the Costco membership the card is self has no annual feeIs there anything specific youre worried about? Its definitely legitimate, and if you shop regularly for essentials at Costco already, its very hard to beat the cash back rates.My only minor issue is that the Citi mobile app kind of sucks. Its quite slow to load and regularly seems to forget about my saved fingerprint. This is a minor issue though of course, Id still recommend the card. 