Mom is in debt with two credit card companies. She has no assets, so what happens when she tells them she can't make payments anymore?

She doesn't need to file bankruptcy because she has no assets that can be attached.

If she has no assets they can't do anything. If they sue her, they can win, but they cannot attach her social security. Just tell them she has no assets and no income. Then don't talk to them anymore. They will just harass her and ask her to borrow the money from relatives.

However, she has to stop using credit cards. Using them and knowing that you can't pay, is the same as stealing.

They have the right to try to collect. Call, sell the debt, file for a lien, whatever the law allows.
You have the right to not be harassed. For examples there are limits as to what hours a collection agency can call, but they can call. You are not responsible to pay, mom is.
Mom like anyone else has the right to file bankruptcy.
At the end of the day, credit companies will not spend too much time chasing collections if there are no assets....good money after bad. They will however sell the debt for pennies on the dollar to agencies that are highly motivated to collect.

If you have Power of Attorney (which I suggest, so you aren't paying for her debts out of pocket - no need to do so), you can simply write the companies and tell them that your mom is ill, elderly, and has no assets. Send this short letter with a copy of the POA form. Usually, this will be enough for most companies to write off the debt and leave you alone.

It's a Dave Ramsey moment. You can Google him. I've heard him address this issue numerous times. I think you'll find something on his web site, or in the local paper or hear him on AM radio. I had the assets to pay off my parent's credit card debt. They wouldn't budge or work with me, either. But they can't squeeze water out of a rock, either. Don't panic, and stay calm when talking to them. And hold your ground. As your Mom's Advocate, state the facts, and don't let them bully you. (They will try, and send the mean sounding ones to intimidate you.) Tell them you will work with them, or they can call an attorney. But don't cave in to their usually unreasonable demands. Check the website above for more tips. He's a pro!

I am in the same situation with my mom. I have taken over making her minimum payments but have also taken over many other financial resposibilities and have my own to manage as well. When she first got sick she missed a couple payments so when I stepped in I contacted the credit card companies to try and work something out. They wouldn't even waive the late fees much less reduce the newly increased interest rates. I made it clear that I was not trying to back out of the responsibility of paying but wanted to work something out that was manageable for me- they wouldn't budge on anything. Hugs to you- you are not alone!