///COMPARISON
Both are legitimate ways to challenge a property tax assessment — they're built for different owners. Here's the factual comparison, with every O'Connor claim cited to their own public pages.
| Castellan | O'Connor | |
|---|---|---|
| Service model | Completes the appeal end to end — researches the county's own assessment records, builds the evidence, files before the deadline, and argues the live hearing. | Annual enrollment-based “Property Tax Protection Program” — appeals filed and represented every year, from informal hearings through coordinating judicial appeals and binding arbitration. |
| Fee structure | Pure contingency — the rate is set by state and quoted in writing before you sign. If the appeal doesn't win, the fee is $0. | Contingency — “half of first year property tax savings” (50%), with no upfront fees. |
| Property types | Commercial and residential. | Commercial in roughly 45 states; residential concentrated in TX, IL, GA, and NY. |
| Where they operate | Georgia, California, and Florida. | Texas-rooted; commercial reach described as ~45 states. |
| Who files & represents | Castellan files and represents the appeal, including the hearing if there is one. | O'Connor staff file and represent enrolled properties annually. |
Competitor information reflects their public materials as of the dates cited and may change — verify with the provider.
Your property is in Texas — O'Connor has been rooted there since 1974 and handles protest volume at a scale few match; Castellan doesn't serve Texas today.
You want set-and-forget annual enrollment with one provider re-protesting every year, and coordination into judicial appeal or binding arbitration when a case warrants it.
You're comparing what a win costs you: O'Connor's published fee is half of first-year savings; Castellan's contingency rate is set by state and quoted in writing before you sign, and is $0 if the appeal doesn't win.
You're in Georgia, California, or Florida and want technology-driven, per-case research on the county's own records rather than volume enrollment.
You want a provider that tells you when you have no case — Castellan files only when the county's own data supports the appeal.
Enter your address and we'll check the county's records at no cost. If there's no case — or another provider genuinely fits you better — we'll say so.
Serving Georgia, California, and Florida today.
Property tax appeals. Any estimate is based on county assessment data and public records and is not a guarantee of any outcome. Representation and fee terms are provided in writing before any filing. Competitor information reflects their public materials as of the dates cited and may change — verify with the provider.