Can someone declare bankruptcy against me?

First of all, you have to declare and file for bankruptcy. Just you and no one else. I would contact your credit card company at once and changed your account number. You are responsible for your bill and I would inform you friend not to use your card no more. I would get some legal doents and have your friend agreed to a payment plan with you so you can pay off your bill. I quickly figured up your balance of $3,500 at 7.99% interest (probably too low) and the minmium payment is around $75 per month. Do you realize it would take you at least four to five years to pay it off with nothing else added on your credit card? Do not ever loan money or go into business with family, friends or relatives. Good Luck.