I am writing a DV letter to a CA for which I haven't a full account number. I never received any correspondence from them; the only information I have on them is that which I found on my CR, which covers the last four numbers of the account number. So far, the only personally identifiable information I'm sending to them is my name, address, and the account number (minus the last four digits). Will this be enough information to legally request a DV? Will I need to include my SSN? Thanks.
I would not DV just yet. Dispute it directly with the CRA. That way if it comes back verified then dispute it with the CA. If they fail to validate then that is a violation that you can use.
In addition, it is likely they don't have much info on you or they would have dunned you. Chances are if you only go through the CRA's it will be deleted in light of this. You DV them, you put them on a higher notice.