Yes, they can still take you to court, unless you are either (1) paying an amount which they agreed to accept (that is, if you come to an agreement with the creditor as to repayment, as long  as you honor your end of  it, they have to honor their end and can't sue); or (2) if you have not defaulted, as long as you equal or exceed the required minimum monthly payment (if any; most credit cards have a minimum which you have to pay each month).However, if you are already in default (paid late; missed payments; didn't make minimums; etc.) and there is no agreement to let  you pay $50 per month, then they can cash your check and still sue you (though at least you'll be credited for any payments you make). That's because once there is a default, the creditor is entitled to seek payment in full of all outstanding debts; also, the debtor is not allowed to unilaterally decide how much (s)he will pay each month.