Oh yeah......actually collection agencies cannot file suit....only attorneys. Credit card companies (and junk debt buyers) routinely hire attorneys with the intent of filing suit.

Hi!
Welcome to the forums!

If you have defaulted on a credit card, then the attorney representing the card company can file a lawsuit against you.

what can I do if I received a summons from an attorney?

You have to answer the summons and appear in court, otherwise the creditor gets a default judgment.

Could you possibly give a little more info? Your question is vague and it is difficult for us to offer assistance without a little background info.