Every year, commercial tenants across the country receive a reconciliation statement from their landlord. The statement says: here is what we actually spent on operating expenses this year, here is your share of those expenses, here is the difference between what you already paid in monthly estimates and what you actually owe.
Most tenants pay it.
A CAM audit is what happens when a tenant decides to check the math first.
What a CAM Audit Actually Is
A CAM audit is a forensic review of a landlord's CAM reconciliation. The goal is to verify that every charge in the reconciliation is (1) actually allowed under the lease, (2) mathematically correct, and (3) properly allocated to the tenant.
"CAM" stands for Common Area Maintenance, but in practice the audit covers everything that falls under the operating expense umbrella — maintenance, utilities, insurance, property taxes, and management fees. Depending on your lease type, that can be a very long list.
The audit process starts with two documents: the lease and the reconciliation statement. The auditor (or in CAMAudit's case, the software) reads the lease to understand what the landlord is permitted to charge, then compares every line item in the reconciliation against those lease terms.
40% of CAM reconciliations contain material errors (Tango Analytics, cited by PredictAP, 2023)
When errors show up — and they show up often — the auditor documents them, calculates the overcharge, and prepares a dispute letter.
What a CAM Audit Examines
There are four areas where overcharges consistently appear.
Pro-Rata Share Calculations
Your pro-rata share is the fraction of the total expense pool you are responsible for. It is calculated as your square footage divided by the total rentable area of the building (or the relevant section, depending on lease language).
A small error in the denominator creates a compounding problem. If the denominator is understated — say, the landlord used 80,000 square feet when the building is actually 95,000 square feet — your percentage goes up, and every expense in the pool gets billed at a higher rate than your lease requires. That error repeats every year, and most tenants never catch it.
Management Fees
Landlords typically charge a management fee as a percentage of the property's gross revenues or the total CAM pool. The fee percentage is negotiated and written into the lease.
What actually gets billed is sometimes higher. The management fee overcharge is one of the most common findings in CAM audits — either the percentage is wrong, or the base the fee is applied to includes expenses that the lease definition excludes.
Excluded Expenses
Every lease has a list of expenses the landlord cannot pass through to tenants. Capital expenditures are the most common exclusion — things like replacing an HVAC system, repaving the parking lot, or renovating the lobby. These are one-time capital investments, not operating expenses, and most leases are explicit about keeping them out of the CAM pool.
Leasing commissions for filling vacant space are another common exclusion. So is landlord overhead — executive salaries, home office allocations, legal fees for lease negotiations. When these show up in a reconciliation under generic line items like "administrative expenses," they tend to get paid without question.
CAM Caps and Base Year Protections
A CAM cap limits how much controllable expenses can increase from one year to the next. If your lease caps controllable CAM increases at 5% and the reconciliation reflects an 8% increase in those line items, you have been overbilled on the difference.
Similarly, if your lease uses a base year structure, the landlord is supposed to bill you for the increase over the base year amount — not the full year-one amount. If the base year was established with an understated expense figure, or if it has been quietly adjusted, you are overpaying on every reconciliation that follows.
Who Needs a CAM Audit
Any commercial tenant who receives a CAM reconciliation has a reason to audit it. That said, audits tend to be most valuable in three situations:
High-dollar reconciliations. If your annual CAM bill is $20,000 or more, even a modest percentage error represents real money. A 10% overcharge on a $30,000 CAM bill is $3,000 — and it likely appeared in prior years too.
New reconciliations that show a large increase. A spike in CAM charges that does not match changes in your building or market conditions is worth investigating. The cause might be legitimate (insurance rates went up, a major repair happened), or it might be an error or an excluded expense that snuck into the pool.
Leases with complex protections. CAM caps, base year provisions, gross-up clauses, and management fee caps all create audit opportunities — because they create compliance requirements the landlord has to meet. If you negotiated those protections, you want to know if they are actually being honored.
What a Traditional CAM Audit Costs
Traditional CAM audits are done by commercial real estate accountants, specialized audit firms, or large accounting practices. The pricing models vary.
Contingency-based auditors charge nothing upfront, then take 25% to 33% of any recovery. If the audit finds a $20,000 overcharge, the auditor keeps $5,000 to $6,600. This aligns incentives — the auditor only gets paid if they find something — but it also means the auditor is selecting for cases with large, obvious errors. Smaller but legitimate overcharges may not be worth their time.
Hourly audits at major accounting firms run $350 to $450 per hour based on public billing rate disclosures from firms like KPMG and Deloitte. A thorough audit of a moderately complex lease can run 10 to 20 hours. That is $3,500 to $9,000 before you know if there is anything to recover.
CAMAudit runs for $79 flat. Upload the lease, upload the reconciliation statement, and get results in under 15 minutes. If the audit finds nothing, you paid $79 to confirm your bill is accurate. If it finds something, you have a documented dispute with exact dollar amounts and a draft letter — ready to send.
What Tenants Find When They Audit
Deloitte research found that up to 70% of commercial tenants identify billing discrepancies when they review their CAM statements in detail. The specific errors vary, but some patterns repeat across property types and landlords.
70% of commercial tenants identify billing discrepancies when they review their CAM statements (Deloitte, 2024)
Management fee overcharges are common — either the fee percentage exceeds the lease cap, or the fee is applied to a base that includes excluded expenses. Capital expenditures billed as maintenance line items appear regularly, often under vague descriptions like "building improvements" or "common area upgrades." Pro-rata share math errors are found often, particularly in multi-tenant buildings where the denominator changes year to year.
Gross-up violations are trickier. A landlord applying a gross-up to fixed expenses — ones that do not actually vary with occupancy — is overcharging, but it requires reading the lease definition closely to catch. The same is true for audit rights violations, where tenants are denied access to supporting documentation they have a contractual right to review.
How CAMAudit Works
I built CAMAudit because the audit process was too expensive and too slow to be accessible to most tenants. A small business renting 2,000 square feet of retail space is not going to hire a $400/hr accountant to review a $15,000 CAM bill. But they should still be able to check whether that bill is accurate.
The process is straightforward. Upload your lease and your CAM reconciliation statement. The system extracts the relevant provisions from the lease — CAM definitions, exclusions, pro-rata share methodology, management fee caps, CAM caps, base year terms — and then runs 14 detection checks against the reconciliation. The math checks are deterministic: the tool calculates what your pro-rata share should be, what the management fee should be, what the CAM cap allows. The classification checks use AI to identify expenses that look like excluded categories — capital expenditures, landlord overhead, leasing commissions.
If overcharges are found, you get a full report with exact dollar amounts and a draft dispute letter grounded in your specific lease language. If nothing is found, you get confirmation that your bill checks out.
FAQ
How long does a CAM audit take?
A traditional CAM audit takes two to eight weeks depending on the auditor's workload, the complexity of your lease, and how quickly the landlord provides backup documentation. CAMAudit processes results in under 15 minutes. The upload takes a few minutes; the analysis runs while you wait.
How much does a CAM audit cost?
A traditional audit costs nothing upfront if you use a contingency auditor (who takes 25-33% of recoveries), or $3,500 to $9,000+ at hourly rates from major accounting firms. CAMAudit charges $79 flat regardless of outcome.
What if the audit finds no overcharges?
Then your landlord's reconciliation is accurate, and you paid $79 to verify it. That is still useful information — it confirms your lease protections are being honored. Some tenants audit every year as a matter of course, the same way they review any significant invoice before paying it.