The Quick Answer

When you file bankruptcy all debts and all assets must be revealed to the Court, and thus listed on your bankruptcy petition. Before trying to pay off any debts, in order to keep a line of credit open, speak to a qualified bankruptcy attorney about your options/limitations.

The Long Answer

If you file chapter 7 bankruptcy, some creditors may offer, or be willing to enter into, something called reaffirmation agreements. These are in essence a new contract you enter into. Under certain circumstances, these agreements must be approved by the court. After receiving notice of a client's bankruptcy some credit card companies will send the bankruptcy attorney a contract in the hopes that the client will be willing to enter into a contract agreeing to keep a credit card, and continue to make payments on the card.

The idea is this. The credit card companies know just how convenient and necessary credit cards have become. They understand that sometimes people may need to file bankruptcy because they have too much debt. But, they also know that people are still willing to hold on to at least one credit card if they can. So, the credit card companies all want to be the one that you hold on to. So much so that some companies have offered to lower the interest rates on the cards, or even the amount outstanding, if the person who filed bankruptcy was willing to keep making the monthly payments on the card.

If you have an attorney it shouldn't be too hard to reaffirm a debt/line of credit. You should speak with your attorney whether or not you will be required to get court approval.

However, keep in mind that creditors change their policies all the time. Also, don't let anyone tell you that they guarantee you can keep any particular card. Typically, it's up to the creditor whether or not they are willing to let you keep your card.