CAM True-Up: What It Is, How It's Calculated, and What Can Go Wrong

What a CAM True-Up Is

A CAM true-up is the annual settlement between estimated CAM payments and actual CAM expenses. Throughout the year, tenants pay a monthly CAM estimate — a landlord's projection of what operating expenses will be. At year-end, the landlord closes the books, runs the reconciliation, and determines what each tenant actually owes based on verified expenses and their pro-rata share.

If the tenant's estimates covered their actual obligation: no payment due. If actual expenses exceeded estimates: the landlord bills the difference (a true-up charge). If estimates exceeded actuals: the landlord issues a credit or refund.

The true-up is not a penalty. It is not a fee. It is an arithmetic outcome — the difference between two numbers: what the tenant paid and what they owe.

When the True-Up Happens

The annual CAM true-up is tied to the landlord's fiscal year-end, not the calendar year — though the two align for most commercial leases.

Calendar-year leases (most common): Fiscal year ends December 31. The landlord spends January closing the books, posting final accruals, and validating GL data. Reconciliation calculations run in February or March. True-up statements go out in Q1, with a target of no later than 90 days after year-end (March 31).

Fiscal-year leases: Same process, shifted. A June 30 fiscal year-end means statements should be delivered by September 30.

What triggers the delivery: Reconciliation completion, not the calendar date. The landlord cannot issue a defensible true-up until the books are closed, all vendor invoices are posted, and the GL data is final. Late vendor invoices — particularly year-end maintenance, snow removal, and property tax installments — are the most common reason reconciliations run into April instead of March.

Most leases specify the delivery window explicitly. Common language: "Landlord shall deliver a reconciliation statement within one hundred twenty (120) days following the end of each calendar year." Miss that window and you have a real problem.

Who Issues It

The landlord issues the true-up statement. Specifically, whoever handles the landlord's CAM reconciliation — typically the property controller or property accountant — runs the calculations and prepares the per-tenant statements. The property manager reviews and approves before delivery.

The landlord's obligation is accuracy, not speed. A true-up statement with errors in the denominator, the gross-up, or the cap structure is worse than a late one — it generates a formal dispute, which costs more to resolve than getting the math right the first time.

How the True-Up Is Calculated

The formula is straightforward. Executing it correctly is where most errors occur.

Core formula:

(Actual Expenses × Tenant's Pro-Rata Share) − Estimates Collected = True-Up Amount

A positive result means the tenant underpaid — they owe more. A negative result means the tenant overpaid — they receive a credit.

Step 1: Total Actual Recoverable Expenses

Pull the prior year's GL for the property. Sum every recoverable expense line item. Apply all required adjustments:

• Remove CapEx. Capital expenditures (roof replacement, HVAC system overhaul, major structural repairs) are not recoverable CAM expenses in most leases. A single miscoded CapEx item inflates the entire pool.
• Remove exclusions. Each lease specifies expenses the landlord cannot pass through — landlord-only costs, above-standard services for anchor tenants, management fees above the capped percentage, etc. Apply tenant-specific exclusions before calculating that tenant's share.
• Apply gross-up. If occupancy was below the lease's gross-up threshold (typically 90–95%), variable expenses must be adjusted upward to reflect what they would have been at the threshold occupancy. Gross-up applies only to variable expenses — janitorial, utilities, security, landscaping. It never applies to property taxes, insurance, or other fixed costs.

Step 2: Calculate the Tenant's Pro-Rata Share

The pro-rata share is the tenant's rentable square footage divided by the building's total rentable square footage — but the denominator is lease-defined, not universal.

Some leases use total building GLA. Some exclude anchor tenant space. Some exclude parking structures. Some use a BOMA-certified measurement from a specific standard year. Each tenant's share must use the denominator their lease specifies, not a single building-wide number applied uniformly.

Pro-rata share = Tenant RSF / Lease-Defined Denominator RSF

Step 3: Apply Lease-Specific Adjustments

• CAM cap: If the tenant has a controllable expense cap, calculate the cap ceiling using the lease's base year and cap percentage (e.g., 5% per year, cumulative or non-cumulative). If actual controllable expenses exceed the ceiling, bill the ceiling amount, not the actual.
• Base year: If the lease uses a base-year structure, the tenant owes only expenses above the base year amount. Calculate the excess.
• Admin/management fee: If the lease permits an administrative fee on top of the expense pool (common: 10–15% of CAM), add it in the sequence the lease specifies — some leases apply the fee before the cap, others after.

Step 4: Subtract Estimates Collected

Sum every monthly CAM estimate payment the tenant made during the fiscal year. Subtract from the tenant's total obligation.

The difference is the true-up amount.

Worked Example

Building: 85,000 SF total rentable area (GLA) Tenant: Suite 210, 10,000 SF Pro-rata share: 10,000 / 85,000 = 11.76% Prior-year annual CAM estimate: $22,000/year ($1,833.33/month)

Wait — that gap is large because the estimate was dramatically low. Let's use a realistic scenario:

The tenant's monthly estimate of $21,250 ($255,000 / 12) was close but slightly short of actual. The true-up bill is $11,637 — less than one month's estimate. This is a well-run reconciliation: estimates were accurate, the true-up is modest, and there is little for a tenant auditor to dispute.

If the tenant overpaid (estimates of $270,000 vs. obligation of $266,637): the landlord issues a credit of $3,363, which is applied to the next month's rent or refunded per lease terms.

What the True-Up Statement Must Include

A defensible true-up statement is not just a number. It is a structured calculation that a tenant — or their auditor — can follow from total expenses to the final invoice. Every statement should include:

Missing any of these invites questions. A statement that shows only "Your CAM balance for 2025 is $11,637" without the supporting math is not a reconciliation statement — it is an invoice with no basis. Tenants are not required to pay it without understanding where the number came from.

Lease Mechanics: Delivery Deadlines and Dispute Windows

Delivery Requirements

Most commercial leases impose a specific deadline for the landlord to deliver the annual reconciliation and true-up. Common windows:

• 90 days after fiscal year-end (landlord-favorable; aggressive)
• 120 days (industry standard)
• 180 days (tenant-favorable; common in larger, more complex leases)

Some leases include a penalty for late delivery. The most common: late delivery does not start the tenant's audit clock, meaning the tenant retains audit rights indefinitely until a compliant statement is delivered.

The most aggressive tenant-favorable language: late delivery constitutes a waiver of the landlord's right to collect the true-up balance. A landlord who misses a 90-day deadline on a $50,000 true-up bill may permanently forfeit that collection.

Tenant Response Window

After receiving the reconciliation, most leases give tenants a window to dispute or request documentation. Common windows:

• 30 days to dispute without further delay
• 60 days to request books-and-records review
• 12–36 months formal audit rights (from statement delivery date)

If a tenant disputes within the window, the landlord must respond. In California, SB 1103 requires response to qualifying commercial tenant documentation requests within 30 days. Ignoring disputes does not make them go away — it escalates them.

The Three Most Common True-Up Errors

These three errors account for the majority of formal CAM disputes and tenant audit findings.

Error 1: Wrong Pro-Rata Denominator

The denominator is the most frequently disputed number in any CAM reconciliation. Using the wrong building square footage — an outdated measurement, a BOMA standard that does not match the lease, or a number that includes space that should be excluded — creates a systemic error that runs through every line item of every tenant's calculation.

How it happens: The denominator used in the property management system was set up when the building opened and has never been updated. A BOMA remeasurement in 2019 reduced the certified GLA from 90,000 SF to 85,000 SF. The system still uses 90,000 SF. Every tenant's pro-rata share is understated by 5.9%.

How to catch it: Reconcile the denominator against the most recent BOMA-certified measurement certificate before running calculations. Confirm the BOMA standard matches what each lease cites.

Error 2: Gross-Up Applied to Fixed Expenses

Gross-up adjustments are legally and contractually permitted only for variable expenses — costs that scale with occupancy. Property taxes, insurance premiums, and management fees are fixed (or semi-fixed) and do not change materially based on how many tenants occupy the building. Applying gross-up to these categories inflates the recoverable pool without contractual basis.

How it happens: A gross-up formula in a spreadsheet or property management system applies the occupancy adjustment to the entire expense pool instead of segregating variable and fixed expenses first.

How to catch it: Before running gross-up, explicitly classify every GL account as variable or fixed. Gross-up applies only to accounts classified as variable. Run the classification step as a discrete, documented step — not as part of the gross-up formula.

Error 3: Cap Not Applied (or Applied Incorrectly)

CAM expense caps protect tenants from large year-over-year increases in controllable expenses. A 5% cumulative cap means the controllable CAM amount can grow no more than 5% per year on a compounding basis from the base year. Failing to apply the cap — or applying it as non-cumulative when the lease says cumulative (or vice versa) — is one of the most common findings in tenant audits.

How it happens: The controller does not have the cap language from the lease abstract, applies a building-wide cap rate where each tenant has a different cap, or confuses the cumulative and non-cumulative calculation methods.

How to catch it: Pull the cap clause from every tenant's lease abstract. For each tenant, calculate the cap ceiling explicitly: (base year controllable amount) × (1 + cap %)^(years elapsed). If actual controllable expenses exceed that ceiling, bill the ceiling. Document which tenants were capped and the calculation.

For a full treatment of cap types and calculation methods, see CAM Expense Caps and Cumulative vs. Non-Cumulative CAM Caps.

True-Up vs. Mid-Year Adjustment: A Quick Distinction

The annual true-up settles the prior year. A mid-year adjustment modifies estimate payments for the current year. They are distinct processes, and confusing them creates billing errors.

If your lease does not permit mid-year adjustments, the entire prior-year shortfall lands in the annual true-up as a lump sum. This is exactly the scenario that generates tenant complaints — and it is entirely preventable with a properly executed mid-year adjustment when the variance is first identified.

See the Mid-Year CAM True-Up guide for the full calculation process.

How CapVeri Handles the True-Up Process

CapVeri generates per-tenant true-up calculations from a GL import. The denominator is verified against the property's certified measurement. Variable and fixed expenses are classified before gross-up runs. Cap calculations use the cap language from each tenant's lease abstract — cumulative and non-cumulative handled separately. Every adjustment is documented with the source GL entries.

The output is a reconciliation statement for each tenant that shows every line in the table above, with the math traceable back to the GL. Audit-ready from the first run.

Related Resources

• Mid-Year CAM True-Up — Adjusting estimates during the year before the annual settlement
• CAM Reconciliation Timeline Checklist — Month-by-month process from GL close to statement delivery
• CAM Pre-Send Checklist — 12-point QA review before any statement goes to tenants
• CAM Expense Caps — Cap types, base years, and calculation methods
• Defensible Reconciliation Package — Documentation to include with the true-up statement

Sources

1. BOMA floor measurement standards — BOMA International
2. IREM CAM reconciliation methodology — IREM Oregon (PDF)
3. California SB 1103 commercial tenant protections — California Legislative Information