A practical guide to auditing your own CAM reconciliation statement, covering all 12 detection checks with what to pull, how to calculate, and what to do when you find an error.
Run the audit before you decide whether this applies to your lease.
Find My OverchargesFind overcharges in your CAM reconciliation. Most audits complete in under 5 minutes.
Find My OverchargesSee a sample report firstTo audit CAM charges: (1) Request supporting documentation (lease, reconciliation statement, general ledger), (2) verify each line item against your lease's inclusion and exclusion lists, (3) apply the 13 detection rules covering management fee, pro-rata share, gross-up, cap, base year, and classification errors, (4) calculate overcharge amounts for every discrepancy found, (5) issue a dispute letter draft if errors are found.
TL;DR: 40% of commercial CAM reconciliations contain billing errors (Tango Analytics, 2023). To audit yours, gather your lease, the reconciliation statement, and the general ledger, then run 13 checks covering lease type, excluded expenses, management fee, pro-rata share, gross-up, cap, base year, insurance, taxes, utilities, and common area classification. Average recovery: 15-20% of total CAM billed.
A CAM audit compares what a landlord billed for common area maintenance against what your lease actually permits. If you want to understand what a CAM audit is before diving into the how-to, see What Is a CAM Audit. For the complete tenant-focused walkthrough, the Tenant CAM Audit Guide covers the full process from document gathering through dispute resolution. 40% of commercial CAM reconciliations contain material errors (Tango Analytics, 2023), and the average recovery rate when an audit is conducted is 15–20% (PredictAP, 2026). When the numbers differ in your favor, the gap is a recoverable overcharge.
This guide walks through all 13 detection checks in the order a trained auditor would apply them. Each check is explained, the key calculation is shown, and the documentation you need is listed. You can do this yourself with your lease, the reconciliation, and the underlying records, or upload both to CAMAudit and run the checks automatically.
Manual audit time: 3–6 hours for a clean set of records. Dollar return: easily 5–10x the time invested.
You need three things at minimum:
Your fully executed lease with all amendments, exhibits, and side letters. The lease is the controlling document for every check in this guide.
The CAM reconciliation statement you are reviewing. This should show expense line items, the total pool, your pro-rata share percentage, and the amount billed.
The CAM general ledger for the reconciliation period. The reconciliation statement shows totals; the general ledger shows the individual expenses behind the totals. Most landlords provide this on request under the lease's audit rights clause.
For a complete audit, you also want:
What this check does: Confirms whether your lease is gross, modified gross, or triple-net, and whether CAM pass-throughs are authorized at all.
How to do it: Find the Rent or Additional Rent section of your lease. Look for language authorizing the landlord to bill operating expenses, CAM, or common area costs as additional rent. If no such language exists, the entire CAM reconciliation may be an overcharge.
What to look for: A gross lease has no pass-through authorization. A NNN lease explicitly authorizes the pass-through. Modified gross leases specify which categories are included.
See: Gross lease CAM charges, when a landlord bills you for costs your lease already covers
What this check does: Identifies expenses in the CAM pool that your lease explicitly prohibits.
How to do it:
Common exclusions: Capital expenditures, leasing costs, insurance proceeds, ground rent, depreciation, above-standard services for specific tenants, entity-level corporate overhead.
See: Excluded service charges: when specific costs are off-limits
What this check does: Identifies major replacement or improvement projects that have been included as operating expenses.
How to do it:
See: Capital expenditures in CAM charges: how major property improvements get billed as maintenance
What this check does: Verifies that the management fee rate and calculation base match the lease terms.
How to do it:
See: Management fee overcharges in CAM statements
What this check does: Verifies that the pro-rata percentage applied in the reconciliation matches the formula your lease requires.
How to do it:
See: Pro-rata share denominator errors: how admin fees and CAM allocations get inflated
What this check does: Verifies that variable CAM expenses were normalized to the lease's target occupancy level in years when actual occupancy fell below that threshold.
How to do it:
See: The CAM Overcharge Detection Playbook, Rule 5 section
What this check does: Verifies that controllable CAM expenses have not exceeded the lease-defined cap.
How to do it:
See: CAM cap violations: cumulative versus compounded calculations
What this check does: Verifies that the base year used in the reconciliation matches the lease's definition and that the base year costs were correctly established.
How to do it:
See: Base year errors in CAM leases: the mistake that inflates every future bill
What this check does: Verifies that insurance costs in the pool are based on actual premiums and include only authorized coverage types.
How to do it:
See: Insurance overcharges in CAM statements: how premium pass-throughs go wrong
What this check does: Verifies that property tax amounts are correctly assessed, cover only the lease-authorized tax categories, and credit any refunds from successful appeals.
How to do it:
See: Property tax overallocation in CAM statements
What this check does: Verifies that utilities billed directly to you are not also included in the CAM pool.
How to do it:
See: Utility double-billing in CAM statements: how tenants pay the same cost twice
What this check does: Verifies that expenses in the CAM pool are actually for common areas rather than for specific tenant spaces or above-standard services.
How to do it:
See: Common area misclassification: when tenant-specific work gets charged to everyone
A CAM audit finding is the beginning of a conversation, not the end of one. For a step-by-step walkthrough of all audit procedures from document gathering through dispute letter drafting, see the full lease audit procedures guide. Most disputes resolve without litigation:
Document the error. Write up the specific check, the lease provision that governs, the amount billed, the correct amount, and the dollar difference. Be specific about the line item and the provision.
Submit an audit letter. Your lease's audit rights clause typically specifies a process for raising disputes. Use it. A formal written dispute preserves your rights and triggers the landlord's obligation to respond.
Allow time for response. Most leases give the landlord 30-90 days to respond to an audit finding. Wait for their response before assuming the dispute is unresolvable.
Negotiate. Landlords often partially concede clear errors while disputing gray-area items. A partial credit may be worth accepting rather than litigating, depending on the amounts involved.
Escalate if necessary. If the landlord disputes a well-documented finding, the lease's dispute resolution clause applies, often mediation before arbitration or litigation. The CAM dispute guide covers this process in detail.
For a tenant doing this manually with complete records: 3-6 hours for the basic checks. A full audit with document requests and investigation of flagged items can take several weeks depending on how quickly the landlord provides documentation. CAMAudit's automated audit runs in under 5 minutes for the primary analysis.
Not for the basic checks. The 13 checks in this guide require arithmetic, careful reading, and organized documentation, not specialized credentials. Professional auditors add value for large, complex properties or when the landlord is resistant to providing documentation. For most tenants, starting with the self-audit approach is appropriate.
Your lease's audit rights clause typically specifies a window, often 60-90 days from receipt of the reconciliation, within which you must raise a dispute or the reconciliation is deemed accepted. Check your specific clause. Statutory limitations periods also apply, typically 3-6 years for written contract claims. Both may run simultaneously: the contractual window for the current year and the statutory period for earlier years.
Yes, and it is often worth doing. CAM errors, particularly pro-rata share errors, management fee base errors, and base year errors, tend to persist across multiple years. A single investigation can surface overcharges from several reconciliation periods at once.
Your lease's audit rights clause typically requires the landlord to make records available within a defined time period. Document the refusal in writing. Refusal to provide documentation is itself a basis for a dispute and strengthens your position if the matter escalates.
The average recovery rate is 15–20% of total CAM billed when an audit is conducted (PredictAP, 2026). On $60,000/year in CAM, that's $9,000–$12,000. Management fee base errors, pro-rata share errors, and capital expenditure misclassification tend to produce the largest single-finding impacts because they affect the entire CAM pool, not just individual line items.
| Method | Cost | Time | Checks All 12 Rules | Min Viable CAM |
|---|---|---|---|---|
| Manual (this guide) | Free | 3–6 hours | If you do each step | Any amount |
| Traditional CPA firm | $17,000–$54,000 | 6–9 weeks | Yes | $100,000+ |
| Contingency boutique | 33% of recovery | 8–12 weeks | Yes | $60,000+ |
| CAMAudit ($199) | $199 flat fee | Under 5 minutes | Yes | ~$1,140 |
Source: PredictAP (2026), KPMG published rates, National Lease Advisors pricing.
CAMAudit runs all 12 of these checks automatically when you upload your lease and reconciliation. The process takes under 5 minutes and produces a prioritized finding report with the dollar amount and lease provision for each identified discrepancy.
See also: The CAM Overcharge Detection Playbook, the technical deep-dive behind each rule. You can also compare all CAM audit service options and pricing. If your lease passes through broad operating expenses rather than a defined CAM pool, see the operating expense audit guide for how the review process differs.
Related: Gross lease CAM charges | Excluded service charges | Management fee overcharges | Pro-rata share errors | CAM cap violations | Base year errors | Capital expenditures in CAM | Insurance overcharges | Property tax overallocation | Utility double-billing | Common area misclassification | Controllable expense cap violations | CAM dispute guide