Service vs. DIY Breakeven Calculator
Last reviewed: May 2026 · Coverage: Texas, California, Illinois, New Jersey, New York, Florida, Massachusetts, Connecticut, Pennsylvania, Ohio, Georgia
Service companies typically charge 25-60% contingency on first-year property tax savings. DIY appeals cost time but no contingency. This calculator estimates the breakeven — the time-value at which DIY starts to make less sense than hiring.
How the calculation works
Service company cost = Annual savings × Contingency rate
DIY time cost = DIY hours × Your hourly time value
Net DIY benefit = Annual savings − DIY time cost
Net service benefit = Annual savings × (1 − contingency rate)
DIY beats service when: DIY time cost < Service contingency cost
State context for contingency rates
- Texas: 25-40% typical for residential. Subscription (annual flat fee) and per-parcel filing-fee models are also common. Major firms: Texas ProTax, O'Connor, Five Stone, Texas Tax Protest.
- California: 25-40% typical. Most CA appeals via Prop 8 informal review don't even need a service company — homeowner can request directly through the assessor's office at no cost.
- Illinois: 25-35% typical for BoR / PTAB representation. Local "flyer-in-mail" consultants often charge 33%+ of one year's savings. Most service companies don't pursue §16-185 rollover follow-up petitions.
- New Jersey: 25-40% typical. Tax Court matters (>$1M) typically attorney-represented at flat or hourly rates rather than contingency. Some Union County firms offer senior/veteran fee waivers.
- New York: 40-60% typical, especially in Long Island (Heller's published rate is 50%; All Island Tax Grievance and similar firms quote in the 40-50% range). NY's higher rates reflect volume-based business model. Article 7 Tax Certiorari typically attorney-represented.
Things that affect the breakeven that this calculator doesn't model:
- Auto-renewal: many service companies auto-enroll clients for subsequent years' filings. Read the contract.
- Multi-year savings: if your state has carry-forward (IL §16-185 rollover, NJ judgment freeze, CA Prop 8 multi-year), the contingency is typically only on year 1 — meaning year 2-3+ savings are 100% yours either way. The calculator focuses on year-1 economics.
- Service company scale advantage: firms file thousands of protests simultaneously and can negotiate informal settlements with CADs/BoRs/CBTs more efficiently than a single homeowner. This shifts the breakeven slightly toward service for marginal cases.
- Outcome quality difference: empirical data suggests well-prepared DIY appeals achieve comparable percentage reductions to agent-filed appeals when the homeowner has strong comp evidence. Service company advantage is volume + filing efficiency, not better evidence.
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