Re: Re: Re: Abbreviations - Equifax inquiries? A DTC inquiry is a DeTCh, which means they typed in your SS# only. usually I think they do that to see if you may have changed your name or if someone is using your SS#. Call up Equifax's sales office at 800-685-5000 and claim your a car dealer or something and would like to apply for thier services; then act confused about the exact services you need; usually they will fax you the sales material on the different types of inquires.