Same owner, different LLC: anyone else running into this on old lists?

Question

Working through some old dialer data and kept noticing the same owner showing up as separate leads across different pulls, just filed under slightly different LLCs or spellings. Trying to get my hands on a real retired list, 5 to 10K records, ideally one that built up over multiple campaigns rather than one clean pull, to dig into this more. Anyone have something like that, or know who might? I would be very grateful. Thank you.

Jason Reed · Answer

That "same owner across different LLCs" thing is one of the most under-appreciated sources of dirty list data. Two things are usually happening: real investors/landlords hold properties in separate LLCs on purpose (liability), so one human owner legitimately shows up as several entities, and on top of that, list vendors don't do entity resolution, so spelling variants ("123 Main LLC" vs "123 Main, L.L.C.") get counted as different leads. The fix that's worked for me is to stop deduping on owner name and dedup on the mailing address instead. The tax-billing address is where all an owner's LLCs usually converge, so clustering by that collapses the duplicates and, as a bonus, surfaces your true portfolio owners (multiple hits on one mailing address = someone worth a personalized call). For studying decay, an aged list stacked across campaigns is the right idea, but you'll learn more building it yourself from repeated county pulls than buying someone's, you'll see the same owners move and refile in real time.

Rajiv Thapa · Answer

Appreciate the breakdown, especially separating the two mechanisms. That distinction matters more than people usually give it credit for.

On the mailing address dedup, I've actually run into a wrinkle with that exact approach. Anytime the address lands on a registered agent service, a property manager, or an attorney handling closings, you get one address that a few thousand completely unrelated owners route through. Cluster on that and you've merged strangers instead of separating duplicates, just a different flavor of the same problem you're describing with name variants.

Curious how you've handled that in practice. Do you filter known registered agent addresses out before clustering, or is there a signal you use to tell "this address converges because it's one owner's LLCs" apart from "this address converges because it's a formation service"? Feels like the kind of thing that only shows up once you're running this at real volume.