CAM Estimate vs. Reconciliation: What the Difference Means for Your Cash Flow

Under a NNN lease, you pay CAM in two stages: monthly estimates throughout the year, and an annual reconciliation that settles the difference between what you paid and what the property actually cost to operate. These two numbers rarely match exactly, and how they diverge matters more than most tenants realize.

The estimate is the landlord's projection. The reconciliation is reality — or at least the landlord's version of it. When the reconciliation shows a large balance due, the question isn't just "do I owe this?" It's "is this calculation correct?" Tango Analytics found that 40% of CAM reconciliations contain material errors (cited by PredictAP, February 2026). A large balance due is sometimes legitimate; sometimes it reflects expenses that shouldn't be in the pool at all.

The estimate: what it is and how it's set

Monthly CAM estimates (also called "estimated additional rent" or "CAM installments") are the landlord's advance collection of operating cost obligations. The landlord sets them at the beginning of each year based on either:

• The prior year's actual costs, adjusted for known changes
• A projection of the new year's expected expenses

Estimates are not an accounting of actual costs. They're a cash flow tool. The landlord uses them to ensure they don't come up short on operating expenses during the year while waiting to reconcile at year-end.

Setting accurate estimates matters for tenants. If the landlord significantly underestimates, you'll face a large reconciliation bill in February or March when cash flow may already be stretched. If the landlord overestimates, you've effectively extended an interest-free loan to the landlord until the credit is returned.

Most leases give the landlord discretion to reset estimates each year based on the prior reconciliation. This means a year with higher-than-expected costs raises the baseline for the next year's estimates, even if those higher costs were the result of a one-time event or an improper charge.

The reconciliation: what it calculates

The annual CAM reconciliation compares two numbers:

Total actual CAM expenses for the calendar year, as recorded in the property's general ledger, allocated by tenant pro-rata share.

Total estimated payments collected from the tenant throughout that year.

The difference is either:

• Balance due (actual > estimates): the tenant owes additional funds
• Credit or refund (estimates > actual): the tenant is owed money back

The math is simple. The inputs are not. "Total actual CAM expenses" depends entirely on what the landlord's property management system has coded into the recoverable expense pool — and that's where errors enter.

How errors compound between estimate and reconciliation

The relationship between estimates and reconciliations creates a compounding problem:

Year 1: Landlord sets estimates based on projected costs. Actual costs come in 12% higher due to a resurfacing project, a management fee calculated on the wrong base, and two months of utility charges from a vacant anchor's space improperly included in the common area pool.

Year 1 reconciliation: Tenant receives a reconciliation bill. Some of that 12% overage is legitimate (actual cost increases). Some is improper (the misclassified charges). Tenant pays without auditing.

Year 2 estimates: Landlord resets estimates based on Year 1 actuals, which included the improper charges. The new baseline is inflated. The tenant now pays elevated estimates for an entire second year.

Year 2 reconciliation: If the same improper categorizations continue, the overcharge persists — and the tenant has now been overpaying for two full years.

This compounding is why JLL reported that 28% of tenants who discovered CAM discrepancies did so on their own, but only a small percentage pursued formal professional audits. The ones who do pursue audits recover an average of 15–20% of billed charges (Tango Analytics data cited by PredictAP, February 2026). That recovery rate reflects real money — across multi-year leases, a persistent overcharge of $0.50/sqft on a 10,000 sqft space is $5,000/year, or $25,000–$50,000 over a 5–10 year term.

What a large reconciliation bill actually signals

A large balance-due reconciliation isn't automatically evidence of fraud or intentional overbilling. Legitimate reasons for a large reconciliation include:

Unexpected cost spikes. Insurance premiums rose sharply in 2022–2024. Snow removal costs are difficult to project. A major maintenance issue that wasn't anticipated when estimates were set.

Prior-year estimates were conservative. Some landlords deliberately set low estimates to keep tenants from complaining about monthly costs. This produces large reconciliation bills but is consistent with what the property actually cost.

Your space grew. If you expanded your leased space mid-year and estimates weren't immediately adjusted, the reconciliation trues up that difference.

Illegitimate reasons for a large reconciliation bill include:

Capital expenditures charged as operating expenses. The single most common form of CAM overcharge. A parking lot reconstruction or HVAC system replacement should be depreciated over its useful life, not charged to tenants in a single year.

Management fees calculated on the wrong base. If the lease caps management fees at 4% of gross revenues but the fee is calculated on revenues that include pass-through charges, the 4% applies to a larger number than the lease intends.

Gross-up applied to fixed expenses. Variable expenses can be grossed up to stabilized occupancy. Property taxes, insurance, and landscaping contracts cannot — they don't change with occupancy levels.

Out-of-pool expenses included. Costs associated with re-leasing vacant spaces, tenant improvements, or above-property management fees that don't meet the lease's recoverable expense definition.

The timing risk

The reconciliation creates a timing risk that most tenants don't fully anticipate:

You pay monthly estimates throughout the year. Then in February or March — often during slower post-holiday months for retail businesses — the landlord delivers a reconciliation bill due within 30 days. For a 5,000 sqft space with a $3,000 balance due, that's manageable. For a 25,000 sqft space with a $15,000–$20,000 balance due, that's a material cash flow event.

Tenants can mitigate this by:

1. Requesting a preliminary year-end estimate from the landlord in November or December. Some landlords will provide an estimate of what the reconciliation will show, giving tenants time to prepare.

2. Setting aside a monthly reserve equal to a modest percentage of your CAM estimate to cover likely reconciliation variances. Even a 5–10% reserve on monthly estimates helps.

3. Reviewing the prior year's reconciliation to understand what categories drove the prior-year balance, which may indicate where the new year's reconciliation will land.

Estimate accuracy as a red flag

Some landlords chronically underestimate to keep monthly costs looking attractive to prospective tenants. If your estimates have been significantly below actual costs for two consecutive years, that's a pattern worth noting — it may be how the landlord structures their leasing pitch.

Other landlords overestimate significantly, effectively using the tenant's advance payments as interest-free working capital. If you've received credits for more than 10% of your annual CAM estimate for two consecutive years, request a revised estimate methodology for the next year.

Frequently Asked Questions

Why are my CAM estimates different from my CAM reconciliation every year?

Because estimates are projections and reconciliations are actuals. The landlord projects what the property will cost to operate at the beginning of the year; the reconciliation reflects what it actually cost. The gap can go either direction — larger-than-expected costs produce balance-due reconciliations, lower-than-expected costs produce credits. A consistent pattern in one direction suggests either systematically optimistic or pessimistic estimation.

How long do I have to pay a CAM reconciliation balance?

Most leases specify payment within 30 days of receiving the reconciliation statement. That payment deadline is separate from the audit deadline, which is typically 30–180 days after receipt. You can pay the undisputed portion while formally disputing specific charges — the two actions don't need to happen simultaneously.

Can I dispute a CAM reconciliation after paying it?

Generally yes, if you're within the audit window defined in your lease. Paying a reconciliation in full doesn't automatically waive your right to challenge it later, but some leases contain language that treats full payment without written objection as acceptance. Review your lease's audit and dispute provisions before paying a large reconciliation without first reviewing it.

What should I do if I can't afford the CAM reconciliation balance?

First, verify you actually owe it — don't assume a large bill is correct without checking. Second, communicate with the landlord early. Most landlords will negotiate a payment plan for a legitimate reconciliation balance rather than start default proceedings. Third, note your audit deadline. If you're in the middle of a review, provide written notice of your intent to audit within the deadline, even if you haven't finished the review.

How are CAM estimates reset after the reconciliation?

The landlord typically adjusts your monthly estimate for the new year based on the prior year's actual costs, with adjustments for known changes in the new year (new contracts, planned capital work, etc.). This reset happens with the delivery of the reconciliation or shortly after. Tenants rarely have contractual rights to negotiate the new estimate, but if you successfully dispute charges in the prior reconciliation, those disputed amounts should be excluded from the new year's estimate baseline.

For a full explanation of the NNN lease billing structure, see the NNN Lease Tenant Guide. To understand how to review a reconciliation statement line by line, read how to read a CAM reconciliation statement.

Want to check whether your reconciliation contains recoverable errors? Run a free CAM scan.