PropGap Pro Workspace — For Licensed Tax Professionals Only
For Tax Professionals — Attorneys, Consultants, CPAs & Enrolled Agents
The Evidence Engine for
Property Tax Professionals
Upload a client address list. Get board-ready comparable evidence kits for every property in under 60 seconds — with NJ Chapter 123 CLR and Texas ARB market value analysis built in. Your licensed staff reviews and files. PropGap does the research.
Free trial: 5 Evidence Kits, unlimited uploads — no credit card. Credits only deduct when a gap is found; no-gap and insufficient-data results are always free.
Rule-based, fully auditable — no AI, no black-box estimates. Used by NJ and TX property tax attorneys and consultants this season.
Want to see the output first? View a sample Evidence Kit →
Already have a key? View your dashboard →
Multiple properties? Upload a batch →
Why PropGap Pro
Built for firms in peak season
Scale Without Adding Headcount
A paralegal spends 45–90 minutes per property researching comps, pulling equalization ratios, and calculating the CLR. PropGap does it in under 60 seconds. Process 5x your current appeal volume in the same season — without hiring.
Legal-Grade Precision
NJ: Full Chapter 123 CLR formula — equalization ratio × median comp MV × 1.15 upper bound — applied per municipality from official 2026 state data. TX: Direct market value comparison aligned with ARB evidence standards. Output is a comparable evidence packet; your firm reviews and files. This is not a consumer estimate tool.
Board-Ready Exhibit Format
Every Evidence Kit outputs a structured PDF: Exhibit A (comparable sales grid), the CLR ratio analysis, and a gap calculation. Formatted to attach as an exhibit to Form A-1 (NJ) or Form 50-132 (TX) — your firm reviews, adds legal strategy, and files. Enterprise clients get their firm name on every page header.
State Coverage
NJ & TX — Built to Legal Spec
Each state has different legal standards for what counts as admissible comparable evidence. PropGap implements the exact statutory methodology — not a generic AVM estimate. The same formula applied by NJ Tax Court; the same market value standard applied by Texas ARBs.
New Jersey
Chapter 123 Engine
May 1, 2026 — revaluation municipalities
TX ARB: May 15, 2026
NJ Chapter 123 (N.J.S.A. 54:51A-6) requires the County Board to reduce an assessment when it falls outside the Common Level Range. PropGap calculates the CLR upper bound automatically for every NJ municipality using the 2026 Director's equalization ratios — the same numbers the tax court uses.
- Auto-applies 2026 equalization ratio for every NJ municipality
- Chapter 123 CLR upper/lower limit calculated per property
- Up to 10 filtered comparable sales enforced to same municipality
- Municipality-normalized comp matching (handles E. Rutherford, Ft. Lee, etc.)
- 3σ price/sqft outlier removal — only high-quality comps pass
- Clearly flags whether AV is inside or outside the CLR band
Pilot opportunity: 26 revaluation-town municipalities (Bergen, Essex, Hudson, Passaic counties) have a May 1 deadline — still time to generate kits and close cases this season.
Texas
ARB Evidence Engine
May 15 protest deadline statewide
Texas allows licensed property tax consultants to represent owners at the Appraisal Review Board (ARB). PropGap generates the market-value and equity comp evidence packet — comparables, gap analysis, and informal vs. ARB escalation guidance. Your firm completes Form 50-132 and files.
- Market value and equity comp analysis for ARB hearings
- Harris, Dallas, Travis, Tarrant, and Collin counties covered
- Comparable evidence packet for Form 50-132 protests (comparables + gap analysis — your firm completes the form)
- Informal hearing vs. ARB escalation guidance by gap size
- Gap < $800 = informal only · $800–$3K = informal first · >$3K = prepare for ARB
- CAD record links included for each subject property
High-volume TX consultants handling 100+ protests per season — this is the window to scale without adding staff.
Workflow
From address to Exhibit A in 4 steps
Submit the address + assessed value
Enter the property address and the assessed value from the client's tax bill. PropGap pulls the property record and comparable sales pool from public data instantly.
Engine runs the full analysis
CLR formula for NJ (equalization ratio applied, upper bound calculated). Market value comparison for TX (equity comps filtered by quality). Outliers removed. Same-municipality enforced.
Download the Evidence Kit PDF
A complete PDF: comparable sales table, ratio analysis, and assessment gap calculation. Formatted as Exhibit A — ready to attach to the petition without additional formatting.
Your firm takes it from here
Your licensed attorney or consultant reviews the output, adds case strategy, and files. You control the legal decision. PropGap supplies the data evidence.
Bulk Processing
Process an entire case list in one session
Upload a CSV with your protest list and PropGap generates individual Evidence Kit PDFs for every property — in parallel, in the background.
CSV Format Requirements
Required Columns
AddressRequiredFull property address including house number, street, city, state abbreviation (NJ or TX), and 5-digit ZIP code.
Assessed_ValueRequiredThe property's current assessed value in dollars, as shown on the client's tax bill. Enter as a plain number — no $ or commas needed.
Example File Contents
# First row is the header — do not change it
Address,Assessed_Value
"123 Main St, Tenafly, NJ 07670",485000
"456 Oak Ave, Fort Lee, NJ 07024",520000
"789 Elm Dr, Montclair, NJ 07042",610000
"101 Pine Rd, Houston, TX 77002",380000
# Up to 30 rows per upload
✓
Supported States
NJ and TX
Full CLR + ARB methodology with pre-filled protest forms for both states.
✓
Max per upload
30 properties
One batch per county or client group — keeps error management clean
✓
Address format
Must include State + ZIP
e.g. "Tenafly, NJ 07670"
Common Mistakes to Avoid
- • Missing ZIP code — the address must end with a 5-digit ZIP (e.g. 07670, not just "NJ")
- • Assessed value of 0 or blank — enter the dollar amount exactly as it appears on the tax bill
- • County or municipality only — must be a full street address, not just "Bergen County"
- • Excel .xlsx format — save as .csv (comma-separated values) before uploading
ROI Calculator
PropGap pays for itself in 2 cases.
Set your season caseload and average case fee.
Break-even
2 cases
to cover $1,200/mo
Season revenue
$24,000
30 cases × $800
Net gain vs. manual
+$2,400
freed research overhead
Capacity to scale
45+ cases
same season, no extra headcount
Break-even = $1,200 / avg fee per case. Manual research overhead estimated at $120/property (2.5 hrs × $45/hr: comp pull, equalization ratio lookup, CLR calculation, outlier review). PropGap Pro is $1,200/mo, billed only in active months — pause between seasons at no charge.
Pricing
One plan. No surprises.
Start with 5 free Evidence Kits across unlimited uploads — no credit card required. Credits only deduct when a gap is found. "Within Fair Range" and "Insufficient Data" results are always free.
The PropGap Guarantee
You only use a kit credit when we find a gap.
Clean properties are free.
If PropGap doesn't find an assessment gap, that property costs you nothing — no credit deducted, no charge. We only get paid when you have a case worth filing.
Pro — Active Months Only
Unlimited Evidence Kits while active. Pay for March, April, May — pause in June. Reactivate next January with your full history intact.
- Unlimited Evidence Kits per month — no per-kit fees
- NJ Chapter 123 CLR analysis or TX ARB equity comps
- White-label: every PDF under your firm name
- Bulk CSV upload — paralegals submit a list, you get a ZIP of kits
- Your access key holds all history from day one — no login needed
- Cancel or pause anytime — no annual commitment
- Priority support — same-day response
Already have a trial key? Ready to subscribe?
Upgrade to unlimited — $1,200/month →Active Months Only — Pause Between Seasons
Pay $1,200 only in months you're actively filing appeals (e.g., March–May for NJ, March–May for TX). Pause in June at no charge. Reactivate next January with your full history intact. No annual commitment, no cancellation fees.
Trial → Subscription upgrade: After your 5 free kits, visit propgap.ai/pro/upgrade and enter your trial key — your history carries over automatically.
Liability cap $3,600 (3 months) for data errors.Terms of Service·Data Processing Agreement·API Docs·Methodology
Professional FAQ
Questions professionals ask before signing up
Answers written for legal and tax professionals — UPL, admissibility, data sourcing, liability.
Does using PropGap expose my firm to unauthorized practice of law risk?
No. PropGap is a data provider and calculation engine — it generates comparable sales research and applies statutory CLR/ARB formulas. Your firm makes all legal judgments, reviews all evidence, and files all documents. PropGap never contacts your clients, never files anything, and never provides legal advice. The licensed attorney or consultant on your team is the practitioner of record. Your bar association may have ethics opinions on property tax data tools — review those before adoption.
Are PropGap's comparable sales admissible in NJ County Board hearings?
Comparable sales evidence is the statutory basis for Chapter 123 appeals under N.J.S.A. 54:51A-6. The comparable sales in PropGap Evidence Kits are sourced from RentCast, which aggregates MLS transaction records and public property data. Your firm is responsible for verifying each comparable sale against county records before filing — RentCast data should be treated as a starting point for comp selection, not a substitute for appraisal review. PropGap generates the analysis package; admissibility is a function of the evidence itself and how your firm presents it.
What is PropGap's data source and how reliable is it?
Comparable sales data is sourced from RentCast, a licensed real estate data platform aggregating MLS transaction records and public county deed records. PropGap applies additional quality filters on top of raw RentCast data: a 5-year recency cutoff (preferring the most recent 3 years), same-municipality enforcement for NJ, and 3σ statistical outlier removal on price/sqft. Equalization ratios for NJ come directly from the NJ Division of Taxation's official 2026 publication. As with any data source, we recommend verifying key comparables against county deed records before filing.
Is PropGap's methodology algorithmic or AI-based? Can it be audited?
Fully rule-based — no machine learning, no black-box estimates. The CLR formula is a direct statutory implementation of N.J.S.A. 54:51A-6 using the official equalization ratios. Every Evidence Kit PDF documents the methodology: equalization ratio applied, comps used and why, CLR calculation shown step by step. The output is auditable and repeatable. If a board or opposing party challenges the methodology, your firm can explain exactly how each number was derived.
What happens if PropGap can't find enough comparable sales for a property?
The system returns a clear 'Insufficient Comparable Data' notice. This typically occurs with highly unique properties, rural markets with thin sales volume, or very recent new construction. Importantly: properties that return insufficient data do not count toward your trial or subscription kit usage — you only consume a kit credit when PropGap successfully generates a gap analysis. Data coverage is strongest in NJ metro counties (Bergen, Essex, Hudson, Passaic, Morris, Union, Monmouth, Middlesex) and TX major metros (Harris, Dallas, Travis, Tarrant, Collin).
If the board rejects our comparable evidence, who is liable?
PropGap is a data tool, not a legal services provider. Your firm's licensed attorney or consultant is responsible for all evidence presented, all legal strategy, and all filing decisions. PropGap does not guarantee board acceptance of any comparable evidence — outcomes depend on the board's review and case-specific factors entirely outside our control. For PropGap's own data errors (e.g., a miscalculated CLR or incorrect equalization ratio), our Terms of Service cap liability at $3,600 (3× the monthly subscription fee). This cap applies only to errors in PropGap's data and calculations — it does not apply to, and PropGap is not responsible for, board rejections, adverse rulings, or any outcome arising from your firm's legal strategy. PropGap does not carry errors & omissions (E&O) insurance. Your firm's malpractice carrier should be consulted before relying on any third-party data tool in filed matters.
Have a question not covered here? info@propgap.ai — we respond the same business day.
Ready to scale your appeal volume?
5 free Evidence Kits — no credit card, no sales call. Results in under 60 seconds on any NJ or TX property.
PropGap is a data and research tool. We do not provide legal advice or file appeals. Licensed professionals retain full control of all filings.