When you're sued by a debt collector, you must respond to the lawsuit with an answer within 20 days or a default judgment will be entered against you. An answer is a written legal document that responds to the allegations in the lawsuit. A default judgment often leads to bank garnishments, wage garnishments, and other involuntary collection efforts. So while it's critical to respond, there are some defenses that should be avoided.
Lack of a signed contract
Many people believe that debt collectors must produce a copy of the contract that the account-holder signed to prevail in a debt collection lawsuit. But there are alternative theories used by debt collectors, such as account stated, that may allow them to prevail by merely introducing credit card billing statements. Account stated is an equitable theory where the debt collector must show that the consumer "assented" to the account by receiving billing statements and not objecting to them within a reasonable period of time. Although there are defenses to this argument, particularly if the plaintiff is a debt-buyer, the point is that a signed contract doesn't have to be produced.
Unfortunately, the fact that you cannot afford to pay the alleged debt is not a defense when you're sued by a debt collector. The issue in a debt collection lawsuit is whether you are legally obligated for the debt, not whether you can afford to pay the alleged debt. That fact that you are unemployed, receive public assistance, or are otherwise "judgment proof" may mean that the debt collector will never collect any money from you. But it is not a legal defense to a lawsuit.
Attempted to pay
While frustrating, the fact that the debt collector refused to work out reasonable payment arrangements with you is not a legal defense to a debt collection lawsuit. Courts do not have the authority to force the debt collector to accept the payment plans or settlements.
Ex-spouse responsible for payment
Just because your divorce decree ruled that your ex-spouse is solely responsible for payment of a joint debt, doesn't mean you cannot be sued for the account by a debt collector. Divorce courts do not have the power to modify contracts between you and a third-party debt collector. You may, however, be able to sue your ex-spouse to repay you for any money you are ordered to pay the debt collector.
Good defenses when you're sued by a debt collector
Now that you know how not to defend a debt collection lawsuit, here are some good potential defenses: statute of limitations, unauthorized and/or fraudulent use of the account; identity theft; incompetent or insufficient evidence; and lack of valid assignment of the debt (usually only applicable in debt buyer lawsuits). This is not an exhaustive list and these defenses may or may not apply to your particular case. Consult with a consumer lawyer in your area for specific advice about your case.