CAM Reconciliation for CPAs: What Commercial Lease Auditors Check

A client sends you a CAM reconciliation statement with a $40,000 balance due. The lease is 80 pages. The reconciliation is a summary report from their landlord's Yardi system. Where do you start?

Commercial lease auditing — specifically CAM reconciliation review — is a distinct discipline within commercial real estate accounting. The framework below covers how experienced CAM auditors approach a reconciliation engagement, from initial document intake through dispute-ready findings.

For context on the underlying process, see what is CAM reconciliation — this guide assumes you already know the mechanics and focuses on the audit methodology.

When clients bring you a CAM reconciliation

Most CAM reconciliation engagements arrive through one of three channels:

Dispute-triggered: The tenant received a reconciliation significantly higher than prior years and wants to know whether the increase is legitimate. Time pressure is highest here — the dispute window may be closing.

Periodic audit: The tenant has never audited their CAM charges and wants a one-time review of the most recent reconciliation, or the last two or three years if the audit rights clause allows it.

Lease renewal context: The tenant is negotiating a renewal and wants to understand whether historical charges were accurate before agreeing to new estimates.

In all three cases, your engagement starts with two documents: the lease and the reconciliation statement. Everything else is backup.

The 12-point forensic framework

CamAudit's 12 detection rules map directly to the checks experienced CAM auditors perform. The rules fall into two categories: math-heavy (deterministic calculations against lease terms) and classification-heavy (assessment of whether expense categories are permissible).

Math-heavy checks

Rule 3 — Management fee overcharge. Find the management fee provision in the lease. It specifies a percentage and a calculation base: controllable expenses, gross revenues, or total operating expenses. Calculate: Maximum fee = Allowable base × Lease cap %. Compare to the actual charge. Common errors: fee calculated on a broader base than permitted, admin fees stacked on top without separate authorization.

Rule 4 — Pro-rata share error. Verify the tenant's pro-rata percentage. Correct % = Tenant RSF ÷ Correct total RSF denominator. The denominator is where most errors hide: anchor tenant exclusions, occupied vs. total leasable SF, outdated BOMA measurements. A 2% denominator error on a $200,000 CAM pool is $4,000/year.

Rule 5 — Gross-up violation. If gross-up was applied, identify which expense categories were adjusted. Run: Grossed-up variable expense = Actual expense × (Target occupancy % ÷ Actual occupancy %). Any fixed-cost category in the gross-up pool — property taxes, insurance, landscaping contracts — is a finding. The occupancy percentage used should match the lease's gross-up provision; the actual data should come from the monthly rent roll.

Rule 6 — CAM cap violation. If the lease has a year-over-year cap: compounded cap is Prior year CAM × (1 + cap %). Cumulative cap is Base year CAM + (cap % × years elapsed × base year CAM). The cap may apply to controllable expenses only — confirm the lease's definition of "controllable" before running the test. Also check whether the cap percentage is entered correctly in the billing system (a 5% cap entered as "5" rather than "0.05" generates a 500% cap).

Rule 7 — Base year error. For gross or modified gross leases: confirm the base year is what the lease specifies. Verify the actual base year expenses match the figure used in the formula. Tenant share = (Current expenses − Base year expenses) × Pro-rata %. Common errors: wrong year designated as base, base year inflated by one-time credits, base year excludes categories that current years include.

Classification-heavy checks

Rule 1 — Gross lease charges. Some tenants have gross leases where CAM is not separately passable. If the tenant is on a gross lease and is being billed CAM charges, the entire reconciliation may be improper.

Rule 2 — Excluded service charges. Pull the lease's exclusions list. Match every reconciliation line item against it. Common items that should be excluded: capital improvements, executive salaries, leasing commissions, legal fees unrelated to tenant operations, financing costs, ground lease payments.

Rule 9 — Insurance overcharge. Verify the insurance premium in the reconciliation matches the actual policy. Request the certificate of insurance and premium invoice. Confirm the policy covers only the subject property and reflects market rates.

Rule 10 — Tax overallocation. Request the property tax bill for the assessment year. Confirm the parcel matches the property. Check whether any tax abatements the landlord received are reflected in the passthrough amount.

Rule 11 — Utility overcharge. Verify utility charges cover common areas only. If the tenant pays utilities directly, check for double-billing. Confirm the billing method matches the lease.

Rule 12 — Common area misclassification. Expenses for tenant-specific areas — individual build-out maintenance, private HVAC units, dedicated security for a single tenant — should not appear in the common area pool.

Rule 13 — Controllable expense cap violation. If the lease has a controllable expense cap separate from the general CAM cap, verify that uncontrollable items (taxes, insurance, utilities) are excluded before applying the cap formula.

Lease-to-statement reconciliation

Before running any formulas, prepare a lease abstract covering these provisions:

• CAM inclusion and exclusion definitions
• Pro-rata share formula (numerator and denominator definitions)
• Management fee: percentage and calculation base
• Gross-up provision: target occupancy, applicable expense categories
• CAM cap: percentage, calculation method (cumulative vs. compounded), base period, definition of controllable expenses
• Base year: year and amount (gross/modified gross leases only)
• Audit rights: scope, deadline, and documentation requirements

Map each provision to the corresponding section of the reconciliation. Discrepancies between what the lease requires and what the reconciliation shows are findings.

Variance analysis techniques

After the line-item review, run a year-over-year comparison between the current reconciliation and prior years. Most leases require the landlord to retain records for at least the audit rights period — request prior-year reconciliations if the client does not have them.

YoY comparison by category. Any expense category increasing more than 10–15% year-over-year without a corresponding change in property operations warrants explanation. Flag for documentation requests.

Management fee as a percentage of total expenses. Calculate the effective management fee rate across years. If the rate increased even though the stated percentage stayed the same, the base changed or additional fees were added.

Gross-up multiplier tracking. If gross-up was applied in multiple years, calculate the effective multiplier each year and compare to actual occupancy records. Significant discrepancies suggest the occupancy data used may not match the rent roll.

Large one-time items. Flag any single line item exceeding $10,000. Request the vendor invoice. Determine whether the expense is a capital improvement that should be amortized.

Working with Yardi and MRI exports

Most commercial landlords run Yardi Voyager or MRI Software. CAM reconciliations generated by these systems have specific structures that affect how you interpret the data.

Yardi CAM reconciliation reports typically include a recovery pool summary, a line-item expense detail organized by GL account code, and a per-tenant allocation schedule. Operating expenses are typically in the 7000 series; capital expenditure accounts run separately. See how to read a Yardi CAM reconciliation for the account structure.

MRI CAM reconciliation reports organize expenses by recovery pool before allocating to tenants. The pool structure can obscure whether anchor tenant expenses are correctly excluded. Request the pool configuration to verify the denominator setup. See how to read an MRI CAM reconciliation for the walkthrough.

From the landlord, request: the full GL export for the property (all accounts, full year), monthly occupancy log or rent roll, vendor invoices for flagged categories, the recovery pool configuration, and the lease abstract used to generate the allocation. The CAM reconciliation request template covers the standard list.

Documentation standards for dispute support

When findings support a dispute, your work product needs to be dispute-ready — meaning it holds up in mediation, arbitration, or litigation. Structure your output to include:

For each finding, document: the lease provision that controls, the figure used in the reconciliation, the correct figure, the dollar impact, and the calculation showing the discrepancy.

Show all math openly. If you are computing a corrected management fee, show the base, the lease percentage, and the result. If identifying a cap violation, show the prior year figure, the cap percentage, the maximum allowed, and the actual charge.

Reference specific lease sections (section number and page), specific GL account codes, and invoice dates for any item you are flagging. Vague references weaken findings in a dispute context.

Also calculate total identified overcharges before delivering the report. Most audit rights clauses require the tenant to pay audit costs if the total overcharge falls below a materiality threshold — often 5% of total CAM for the period. The client needs to know this before deciding whether to proceed with a formal demand.

For how these findings translate into demand letters, see how to write a CAM dispute letter.