Common Area Maintenance charges represent one of the largest variable costs in a commercial lease. They are also the most frequently disputed. Industry studies consistently find that 70% to 80% of CAM reconciliations contain at least one error, with average discrepancies ranging from 5% to 15% of total charges.
This guide covers the full CAM reconciliation lifecycle: what CAM charges include, how reconciliation works, what audit rights you should have, and how to identify and recover overcharges.
What CAM Charges Actually Cover
CAM charges are the tenant's share of operating and maintaining the common areas of a commercial property. The specific expenses included vary by lease, but typical categories include:
Property maintenance. Landscaping, snow removal, parking lot maintenance and striping, exterior lighting, signage maintenance, and general building upkeep.
Building operations. HVAC maintenance for common areas, elevator maintenance, fire and life safety systems, pest control, and janitorial services for lobbies, hallways, and restrooms.
Property management. Management fees (typically 3% to 5% of collected rents), on-site management salaries, and administrative costs.
Insurance and taxes. Property insurance premiums, general liability insurance for common areas, and in some lease structures, real estate taxes.
Utilities. Common area electricity, water, and gas, though some leases meter these separately.
The critical distinction is between what the lease says is included and what the landlord actually charges. These two things do not always match, and the gap is where overcharges live.
How CAM Reconciliation Works
Most commercial leases with operating expense pass-throughs follow a two-step billing cycle:
Monthly estimates. At the beginning of each calendar year, the landlord prepares a budget of estimated operating expenses. The tenant pays their pro rata share monthly, based on this estimate.
Annual reconciliation. After year-end, the landlord tallies actual operating expenses and compares them to the estimates. If actual expenses exceeded estimates, the tenant owes the difference. If estimates exceeded actuals, the tenant gets a credit.
The reconciliation statement typically arrives 90 to 120 days after the calendar year ends. It should include enough detail for the tenant to verify the calculations.
In practice, reconciliation statements range from crystal clear to deliberately opaque. Some landlords provide line-item detail. Others provide a single number with minimal backup.
Essential Audit Rights
Your lease should include specific audit rights provisions. If it does not, you are relying on the landlord's accuracy without any verification mechanism. Here is what strong audit rights look like:
Exercise window. You should have at least 120 days from receipt of the annual reconciliation statement to request an audit. Some leases give only 30 or 60 days, which is often not enough time to engage an auditor and complete the review.
Auditor selection. You should have the right to choose your own auditor, whether that is an in-house accountant, a CPA firm, or a specialized CAM audit firm. Some leases restrict you to CPAs only, which limits your options.
Access to records. The landlord must provide access to all supporting documentation: invoices, contracts, payroll records for on-site staff, insurance policies, and tax bills. Verbal summaries or partial records are not sufficient.
Contingency fee auditors. Some leases prohibit auditors who work on a contingency fee basis (they get paid a percentage of what they recover). Landlords argue this creates a conflict of interest. In practice, contingency-based auditors are often the most thorough because their compensation depends on finding real errors. Try to avoid this restriction.
Landlord-paid audit threshold. If the audit reveals an overcharge above a certain percentage (typically 3% to 5%), the landlord should pay for the audit. This provision aligns incentives: landlords who bill accurately have nothing to worry about.
No confidentiality restrictions. Some leases include a clause preventing tenants from sharing audit results with other tenants in the building. This benefits the landlord exclusively. Push back on this provision.
Common CAM Overcharges
After reviewing thousands of CAM reconciliations, certain patterns of overcharges appear repeatedly. Knowing what to look for makes audits more efficient.
Capital expenditures classified as operating expenses. A new roof, parking lot repaving, or HVAC replacement are capital items. Unless the lease specifically includes them in operating expenses (with an amortization schedule), they should not appear in CAM. This is the single largest overcharge category, sometimes adding $2 to $5 per SF in a single year.
Above-market management fees. The lease caps management fees at 4% of collected rents. The reconciliation shows 5% or 6%. Or the fee is calculated on gross potential rent rather than collected rent, inflating the base.
Expenses for vacant spaces. The landlord includes expenses for maintaining, marketing, or improving vacant suites in the operating expense pool. Most leases exclude these costs, but they frequently show up anyway.
Double-counted expenses. An expense appears in two categories. For example, a landscaping invoice shows up under both "grounds maintenance" and "exterior maintenance."
Controllable expense cap violations. The lease caps controllable expense increases at 5% per year. The landlord applies the cap to total expenses rather than controllable expenses only, or does not apply the cap at all.
Excluded expense inclusion. The lease explicitly excludes certain expenses (executive compensation, leasing commissions, legal fees for lease negotiations), but they appear in the reconciliation under generic categories like "administrative costs."
Running a CAM Audit
A structured audit follows a consistent process:
Step 1: Gather your lease terms. Before looking at a single invoice, compile the CAM provisions from the lease and all amendments. What is included? What is excluded? What caps exist? What is the base year? What is the pro rata share calculation method?
Step 2: Request documentation. Send a formal audit request to the landlord within the exercise window specified in your lease. Request the general ledger, all supporting invoices, service contracts, insurance policies, tax bills, and any other documentation referenced in the reconciliation.
Step 3: Verify the pro rata share. Confirm that the square footage used in the calculation matches your lease. Check whether the denominator is total building SF or occupied SF -- this distinction matters significantly in buildings with vacancy.
Step 4: Categorize every expense. Map each line item to either "included" or "excluded" per your lease terms. Flag any expense that does not clearly fall into either category.
Step 5: Check caps and limits. Verify that management fee caps, controllable expense caps, and any other limitations in the lease have been properly applied.
Step 6: Compare year-over-year. Large year-over-year swings in specific categories often signal classification errors or one-time expenses that should not be in operating costs.
Step 7: Document and present findings. Prepare a detailed report of discrepancies with supporting evidence. Present it to the landlord's property manager with a specific dollar amount for the requested credit or refund.
Dispute Resolution
When an audit reveals overcharges, resolution usually follows one of three paths:
Informal negotiation. For smaller discrepancies (under $10,000), most landlords will issue a credit against future CAM payments once presented with clear documentation.
Formal dispute process. Some leases include a dispute resolution mechanism, such as having both parties' auditors meet to reconcile differences. This works well when the disagreement is about classification rather than intent.
Legal action. For significant overcharges where the landlord refuses to correct, the lease may provide for mediation, arbitration, or litigation. This is rare but sometimes necessary, particularly for repeated or egregious overcharges.
Building a System for Ongoing Compliance
A single audit is useful. A systematic approach to CAM verification is far more valuable. The process starts with accurate lease abstraction so that every CAM provision is documented and accessible. When you know exactly what each lease says about operating expenses, reviewing the annual reconciliation against those terms becomes a straightforward comparison rather than a research project.