Surviving a Tenant CAM Audit

Sophisticated tenants audit CAM. Larger ones do it routinely, and specialist firms work on contingency, taking a share of whatever they recover — which means they are thorough and they know exactly where to look.

An audit is not an accusation. It is a contractual right, and handling one well is mostly a matter of being able to produce what was already true.

What auditors ask for

Expect a request covering:

• General ledger detail for the expense pool
• Supporting invoices above a threshold
• The exclusions applied, itemized
• The gross-up calculation with the occupancy basis
• The building rentable area and how the pro-rata share was derived
• The base year figure and its derivation
• The cap test, showing reference and ceiling
• Estimates billed and how they were netted
• The management or administrative fee basis

The question is never “what is the number.” It is “how did you get it, and show me.”

The findings that come up most

Inconsistent gross-up. Grossing up the current year but not the base year. Very common, and it compounds across every year since the lease began.

Capital in the pool. Costs that should have been excluded or amortized, billed as operating expense. The largest single category of recovery by auditors.

Denominator problems. A building area that changed without the lease being amended, or a leased-area denominator combined with gross-up, double-counting vacancy.

Cap ordering. Testing the cap before the base-year deduction, which lets through larger increases than the lease permits.

Administrative fee scope. Fee applied to taxes and insurance where the lease limits it to controllable costs, or applied before exclusions rather than after.

Affiliate transactions. Services provided by a landlord affiliate at above-market rates. Most leases require them to be at market, and auditors check.

Preparing before the request

The preparation is not something you do when the letter arrives. It is what you did during the reconciliation.

What makes an audit straightforward:

• Every intermediate value retained, not just the final charge
• Exclusions itemized with reasons
• The occupancy basis recorded on the gross-up line
• The share calculation showing both areas
• Prior-year reconciliations still reproducible in their original form

That last point deserves emphasis. If your engine or your assumptions changed, prior reconciliations must still show what was actually billed at the time. A trace rewritten to match current logic is a falsified record, and an auditor who spots it will escalate from a routine review to something considerably less pleasant.

Why spreadsheets struggle here

A workbook edited over three years cannot establish what it computed in year one. Formulas have changed, cells have been overwritten, and there is no version history. You can usually reconstruct the arithmetic; you cannot prove it is what you billed.

That is the specific gap a retained calculation trace closes — every reconciliation keeps its inputs and intermediates, and prior versions are never rewritten.

Handling the process

Respond within the lease deadline. Audit rights usually carry response windows, and missing one can shift the presumption against you.

Provide what is asked, not more. A cooperative but scoped response is better than either stonewalling or an undifferentiated document dump.

Check their math too. Contingency auditors are motivated to find issues, and not every proposed finding is correct. Some are aggressive readings of ambiguous clauses.

Fix what is genuinely wrong, portfolio-wide. If an audit finds an error affecting one tenant, it probably affects every tenant in that pool. Correcting only the one who complained is a bad position to be in when the next audit arrives.