Look the company up yourself: your state's licensing site, their real website, not the voicemail. If you call at all, call the number you found; a faked caller number only works from their message. Before you talk, ask for it in writing: the amount, who the original creditor was, and the itemized breakdown. Federal law. "Today or else" is the tell. And never give a card or bank number to "confirm your identity."
Not sure it is real? BillFighter writes the letter that makes them prove the debt, the one a fake collector cannot answer.
Check your bill — freeThe check is free. The letter is the paid part: you print and mail it yourself, or we send it by certified mail for you. No account needed to start.
This is the general rule, in plain words. BillFighter is not a law firm and does not give legal advice. If you have been served with court papers, that is the day for a lawyer or legal aid.