Pro-Rata Share Error: How One Wrong Number Inflates Your Entire CAM Bill
Even a 1% error in your pro-rata share fraction compounds across every line item in your CAM statement. On a $100,000 total CAM bill, that's $2,500 in overcharges every year from a single number.
Definition
A pro-rata share error is a miscalculation in the fraction used to allocate common area expenses to a specific tenant. The pro-rata share is typically the tenant's rentable square footage divided by the total rentable square footage of the building or applicable CAM pool. Because this fraction is applied as a multiplier to every single line item in the CAM reconciliation, even a small error in the denominator or numerator produces an overcharge that compounds across the entire bill. Errors arise from using the wrong denominator by excluding vacant space from the pool, an incorrect numerator from a faulty measurement of the tenant's space, or misapplication of custom allocation provisions written into the lease. CAMAudit's pro-rata share detection rule extracts the lease-defined components of the fraction and compares them against what the landlord actually applied in the reconciliation, then calculates the dollar overcharge produced by any discrepancy.
The pro-rata share fraction is the multiplier applied to every line item in your CAM statement. Errors in this single number inflate your entire bill proportionally.
How we detect
- 1
CAMAudit extracts your pro-rata share percentage and its components from your lease: your leased square footage as the numerator and the applicable building or project square footage as the denominator. CAMAudit also identifies whether the lease uses a fixed percentage for the entire term, a recalculated annual percentage, or a custom allocation formula.
- 2
CAMAudit's pro-rata share detection rule compares the share used in your reconciliation against the figure computed from the lease definition. When the landlord applied a different percentage, CAMAudit flags the discrepancy and calculates the overcharge by multiplying the variance by the total CAM pool charged that year.
- 3
CAMAudit checks whether the denominator definition matches common manipulation patterns. Landlords sometimes exclude vacant space from the denominator, which shrinks it and inflates each remaining tenant's share. Your lease should specify whether the denominator is fixed or adjusts for occupancy, and CAMAudit flags when the landlord has departed from that specification.
Real-world example
A tenant leased 4,800 sq ft in a 60,000 sq ft building. Their lease specified a fixed pro-rata share of 8.0% (4,800 / 60,000). The reconciliation applied 10.2%, noting the building had 47,100 sq ft of occupied space. The landlord was excluding vacant units from the denominator. CAMAudit flagged the variance: on a $185,000 CAM pool, the tenant was billed $18,870 instead of the correct $14,800, a $4,070 overcharge for that year alone.