Double billing in CAM reconciliations is less common than overcapped management fees or incorrect denominators, but when it occurs, the pattern is harder to catch because no single line item looks wrong on its own. The problem only becomes visible when you compare two or more line items against each other and against the underlying invoices.
Here's how duplicate charges enter a reconciliation and how to identify them.
How Double Billing Happens in Practice
Property management accounting systems aggregate costs from multiple sources: vendor invoices, payroll, utility bills, insurance certificates. When a cost passes through more than one route into the CAM schedule — or when a catch-all category overlaps with a specifically named category — the same dollars end up billed twice under different labels.
This isn't always intentional. It often traces to:
- A cost coded to two general ledger accounts, both of which feed into the CAM schedule
- A vendor invoice paid by both the management company (as overhead) and as a direct expense (as CAM)
- A restructured accounting system that moved costs between categories without removing them from their original category
Pattern 1: Administrative Fee + Management Fee
What to look for: Both a "Property Management Fee" line and an "Administrative Fee," "Accounting Fee," or "Supervisory Fee" line in the same reconciliation, each representing a percentage of CAM expenses.
Why it's a duplicate: Most NNN leases define the management fee as covering "all costs and expenses of managing, supervising, and administering the property." That definition encompasses administrative and accounting functions. A separate administrative fee charged on top of the management fee bills the same overhead twice under different names.
How to verify: Pull your lease's management fee definition. Read it carefully for language like "including all administrative, clerical, and supervisory costs." If administrative functions are within scope of the management fee, the separate administrative fee is a duplicate.
What to calculate: Add both lines together and compare to the management fee cap. If the combined total exceeds the cap, you have both a duplicate billing argument and a cap violation argument.
Pattern 2: Utility Direct Pass-Through + Utility Inside Maintenance Line
What to look for: A specific utility line (e.g., "Parking Lot Electricity" or "Common Area Electricity") alongside a maintenance category that also includes utility costs. This can occur when a maintenance service contract includes electricity for the maintained equipment and that electricity cost is also billed separately.
Why it's a duplicate: Exterior lighting electricity billed as "Electricity — Common Area" and also embedded in an "Exterior Lighting Maintenance" line from a full-service lighting maintenance contract (which typically includes the electricity cost) means you're paying for the same electricity through two channels.
How to verify: Request the lighting maintenance contract. Full-service contracts typically state "includes electricity" or "all-inclusive." If the contract includes electricity, the separate electricity pass-through for the same equipment is a duplicate.
Pattern 3: Insurance Billed Separately and Inside "Operating Expenses"
What to look for: A specific "Insurance" line in the reconciliation alongside a broader "Operating Expenses" or "Building Operations" category that, when you examine it, also includes insurance allocations.
Why it's a duplicate: If the landlord uses a blanket operating cost allocation for a portion of the insurance premium AND separately bills a specific insurance line, the same insurance dollars may be counted twice. This can happen when an insurance cost is part of a bundled property management fee that includes insurance allocation and is then also itemized separately.
How to verify: Request the general ledger account codes for the insurance line and for the broader operating expenses line. If both reference the same source transaction, it's a duplicate.
Pattern 4: Management Company Overhead as Both Management Fee and Direct Expense
What to look for: Costs that are typically management company overhead appearing both as a component of the management fee and as a separate direct expense line. Examples: property management software fees, background check costs for hiring maintenance staff, management company vehicle expenses, photocopying and mailing for tenant communications.
Why it's a duplicate: If the management fee is defined as "all costs of managing the property" — and it almost always is — then the management company's internal overhead costs (software, vehicles, communications) are subsumed within the management fee. Billing them separately as direct property expenses in addition to the management fee means they appear twice.
How to verify: Review each line item that could plausibly be management company overhead. Cross-reference against the management fee definition: if the definition includes "all costs," those overhead items should not appear separately.
The General Ledger Request
The general ledger (GL) is the accounting document that shows every transaction that was coded to the property for the year. Each line item in the CAM reconciliation should trace to one or more GL entries. Each GL entry should trace to one vendor invoice, payroll record, or utility bill.
When you suspect a double billing, you're looking for the same source document (same invoice, same payment) appearing in two different GL accounts, both of which feed into the CAM schedule.
How to request it:
Under your NNN lease's audit right, you're entitled to examine the landlord's books and records for the CAM year. Request "the general ledger for all operating expense accounts coded to [property address] for the reconciliation period [dates]."
The landlord's property manager may push back or offer a summary instead of the full ledger. The full ledger is what you need to identify duplicate source transactions. Be persistent — your audit right is contractual.
Cross-Referencing the Expense Schedule
When you have the GL:
Step 1: For each line item in the reconciliation, identify the GL account(s) that feed it.
Step 2: Search for the same vendor name or invoice number appearing in more than one GL account. The same invoice from a janitorial contractor, for example, shouldn't appear in both "Janitorial — Common Areas" and "Building Operations — General."
Step 3: When you find a transaction in two accounts, trace both accounts to the reconciliation. If both are in the CAM schedule, you have a documented duplicate.
Step 4: Quantify the duplicate. The overcharge is the amount of the duplicated transaction multiplied by your pro-rata share.
Start the Verification Process
Manually cross-referencing a CAM schedule against a general ledger is time-consuming and requires the GL to be in a reviewable format. Start with the simpler checks: compare your management fee and administrative fee to your lease cap, look for utility lines that overlap with all-inclusive service contracts, and flag any overhead-type costs appearing as direct expenses.
For a faster diagnostic pass, upload your reconciliation and lease to CAMAudit. The tool flags line item patterns consistent with common double-billing structures and generates a documentation request list for items that need GL-level verification.
Frequently Asked Questions
How common is double billing in CAM reconciliations?
It's not universal, but it appears with enough regularity that it's worth specifically checking for. It tends to occur most often after a management company transition, when the new management company imports historical expense categories without auditing for overlaps, and in properties with large expense pools that are less carefully reviewed.
Does double billing have to be intentional to be disputable?
No. Whether the duplication was intentional or a system error is irrelevant to your right to dispute it. You're entitled to pay only for expenses that comply with your lease terms. An accidental double billing is still an overcharge.
What if the landlord says the two lines cover different services?
Ask for documentation proving the services are different — specifically, two distinct vendor invoices or GL entries for distinct costs. If the documentation supports that the two lines genuinely represent different expenses, there's no duplication. If the landlord can't produce separate documentation, the duplicate billing stands.
Can I request the vendor contracts for all service providers?
Yes, under your audit right. Vendor contracts will reveal whether a service is all-inclusive (supporting the argument that related costs shouldn't be billed separately) or limited in scope (potentially supporting the landlord's argument that an additional cost is genuinely separate).
What's the best order of operations for checking double billing?
Start with the management fee and administrative fee comparison (a quick lease-based check). Then look for utility costs embedded in service contracts. Then check for insurance appearing in multiple categories. Then, if those checks flag something, request the GL for detailed tracing. The GL request is the most resource-intensive step; confirm you have a specific hypothesis before requesting it.
How does double billing interact with the management fee cap?
If an administrative fee is genuinely a duplicate of the management fee, and you add both together, the combined total may exceed the management fee cap. That gives you two independent arguments: the duplicate billing argument (same cost charged twice) and the cap violation argument (total exceeds the contractual maximum). Both are valid; document both.