How to pay off past due assigned to Collection Agency? There is a legal process known as "accord and satisfaction." If you owe the money and at least dispute part of it, or dispute the debt in its entirety, then you can use this process.

My suggestion would be to contact them and see what the bill is for, don't agree to any payments over the phone, determine if they have any settlement authority.

If it is a debt of yours, then you will want to send them a letter with a check. The letter should explain that you are in good faith disputing all or some of the debt and that the enclosed check (suggest about $30-35) is for payment in full of the debt and acceptance of the check signifies their acceptance as payment in full AND that they will completely remove all reports to the major credit bureaus. The check would need to be restrictively endorsed also.

If you don't owe the money, there are several tactics you can take, but they are often time consuming and costly. It may involve filing suit against them, which would mean suing them where they are at (probably another state) so attorney's fees (which you may be awarded if you win, but don't count on it), court costs and simply your time and energy would have to be expended.