How Business Rates X-Ray decides what looks unusual
There is no secret “appeal score”. The tool uses transparent arithmetic and deliberately separates facts, comparisons and relief questions.
1. Change since the previous list
If you enter a 2023 value, the tool calculates the percentage change to 2026. A large increase is labelled as something to understand, not proof of error.
2. Rateable value per square metre
The tool divides the 2026 RV by the floor area you enter. This is an orientation metric. It is only as good as the area and the relevance of the valuation approach.
3. Comparator screen
If you enter comparator £/m² figures, the tool calculates their median. A result 15% or more above that median creates an investigation signal; 25% or more creates a stronger signal. These are product test thresholds, not VOA rules, legal thresholds or professional valuation standards.
4. Property-fact uncertainty
If you say the underlying property facts are wrong or uncertain, that can outrank the comparison signal. The system should not pretend its arithmetic is stronger than its inputs.
5. Relief thresholds
The tool flags when a move from the 2023 RV to the 2026 RV crosses the normal Small Business Rate Relief ceiling. That flag explains a possible bill effect. It does not determine final eligibility.
6. Basic bill estimate
The tool uses the current 2026/27 general England multipliers for non-RHL property types: 43.2p below £51,000 RV, 48.0p from £51,000 to £499,999, and 50.8p at £500,000+. It explicitly excludes reliefs, transitional rules, City of London differences and other adjustments.
Data handling
The current tool calculates in your browser and stores only a copy of the last result in your own browser storage. The free tool has no server-side submission endpoint.
When the answer is “get a professional”
Specialist property types, unusual valuation methods, high-value disputes, uncertain comparables or material legal/procedural questions should be escalated to a suitably qualified rating professional.