I have a letter from a collection agency asking for payment on an account that does NOT appear on any of my credit reports. In the event that I'm sued for this debt, I have absolutely NO records to prove that the SOL has run out (even though I'm sure the SOL has indeed run out). Since it does not appear on any of my reports, there is no date of last activity to refer to. Because of this lack of documentation, would I be better off to send a Validation letter to the collection agency first or just go ahead with a C&D. If I send the C&D and they reply that they will sue me, do they have to Validate the debt before they sue and send me copies of the Validation? Thanks very much.