You raise a very good and important question. what information is a debt collector required to provide, either when they first contact you about a debt, or when they verify your debt upon request. Unfortunately, the federal Fair Debt Collection Practices Act does not spell out what what kinds of details must be included when the data is verified.
So far this issue has been left up to state law, and or judges in the case of debt collection law suits.
With debt buyers buying very old debts, there's a real risk that the amount they are trying to collect is not correct. Even the Federal Trade Commission has discussed the fact that this is a problem for some consumers.
I'm not sure what your situation is. Do you believe the debt collector is trying to collect an incorrect amount? Have you requested verification of your debt as is your right under the FDCPA?
Feel free to share some additional information using the comments link below, and we'll try to point you in the right direction.