<prompt> Human: Last year, my ex-wife asked me to co-sign a loan at her credit union to pay off her bills. Not being the brightest bulb in the marquee, she forgot I had done this, and got with a debt consolidation outfit. Apparently, the mode of operation for these debt consolidators is simply NOT TO MAKE ANY PAYMENTS in this case, to the credit union and force them into renegotiating the amount owed. For months, I got letters from the credit union saying my account was overdue. Every time I got one of these letters Id call my ex and complain. She eventually revealed that she forgot I had co-signed and got this debt consolidation business involved. I told her I wanted to receive no more letters like this and she manged somehow to get me off the nasty letters list at the credit union.Because I am an idiot nice guy, I had just co-signed a car load for one of my sons last month, who has terrible credit. Signing those papers, I noticed that my credit score was an 810 or close to it.Fast forward to last night when I get an email from my bank that there was new activity on my credit score. My new score: 635.This is a Transunion rating now. What can I do to make this go away, or at least reduce the negative effect?  <response>: You co-signed for this, so any late payments are as much on you as they are on her. And they can also sue you for the amount sheyou owes. It is unfortunate, but that is what co-signing means. And yes, it also has a big impact on your credit score. If you want to improve your credit score, you might want to read the wikipages about credit improvement . 