It is usually not wise to pay an alleged debt until you determine who the alleged creditor was, agree that it is legitimate, and the asserted amount is correct.
The FDCPA has a debt verification process designed to enable creditors to get that information.
The process begins by a requirement that, once a debt collector has iniiated collection on a debt, of which reporting to a CRA is considered to be an act of initiating collection, they are required to send you a formal collection (dunning) notice within 5 days, informing you of the name of the alleged creditor, the amount of the alleged debt, and of your right to request that they verify the debt by sendind a written request, called a DV request, to them within 30 days of receipt of their dunning notice.
If you did not receive dunning notice, they are in violation of their debt collection practices obligations.
You can either locate their name from your credit report or call the CRA and attempt to get their name and address, and then send them a DV request.
How to deal with the collector will depend upon its legitimacy.
Starting Score: 565