and one time I went with my Dad and my Dad presented the card to the cashier, then I try to pay. The cashier stopped me and ask if I am a Costco member. I say no and they don't allow me to even pay for the stuff. Therefore, my Dad helped me to pay.....
So, only the Card holder can buy and pay at Costco....
just ask your friend to buy you a gift card for you. Then you could go and use it by yourself. Only bad thing when using the gift card is that you can't enjoy those discount on the flyer since they are for members only.
Don't ever, ever, ever use somebody else's membership card. They check the photo on the card every time and may seize it from you if they find you are using somebody's card. And your friend may have trouble getting it back.
Ask your friend to get you a gift card and you can shop any time you like. However, try not to buy something for $500 with a $50 gift card. You may not be allowed to do so. Get a, say, $500 gift card and you can use it more than once.
My hubby and I are Costco members and I don't even let my daughter use my card. I give her a gift card instead and it works all the time !