Chapter 1 · CAM true-up

What is a CAM true-up?

Guide · August 2026 · Not legal or accounting advice

A CAM true-up is the year-end settlement of common-area maintenance charges. During the year you paid monthly estimates. After the books close, the landlord compares those estimates to the actual recoverable pool and either bills a shortfall or issues a credit.

Definitions: CAM, estimates, reconciliation, true-up

CAM means common-area maintenance — the shared costs of running the parts of a property that more than one occupant uses. The lease, not a dictionary, decides the list. Typical buckets are landscaping, parking-lot sweeping, common-area utilities, janitorial in shared halls, snow, security, and ordinary repairs. Some leases fold real-estate tax and insurance into the same envelope and still call the packet “CAM.” Others keep those lines separate. Read the definition of Operating Expenses, Common Area Costs, or Additional Rent in your lease. If the definition is silent on a cost, the cost is not automatically recoverable because it appeared on a ledger. See operating-expense pass-throughs for the wider category, and NNN true-up when tax and insurance travel with CAM.

Estimates are the monthly or quarterly installments you already remitted against that year’s CAM. They are additional rent, not a final invoice. Paying them on time is not an agreement that the year-end pool is correct. It is compliance with the installment the lease required. The estimate may be last year’s actuals divided by twelve, a landlord budget, or a stipulated dollar amount in an exhibit. Whatever the source, it is a deposit against a later accounting.

Reconciliation is the process. Books close. Recoverable costs are totaled. The lease’s allocation rules are applied — pro-rata, and often a gross-up, an administrative or management fee, and a controllable cap. Estimates are subtracted. A statement is issued. People also call this the year-end adjustment or the operating-expense settlement.

True-up is the settlement number that comes out of that process: your share of the recoverable pool minus estimates paid. A positive number means you owe. A negative number is a credit. A number near zero means the estimates were close.

Why landlords use monthly estimates

CAM is incurred all year. Invoices for landscaping, utilities, and insurance arrive monthly. A landlord that waited until December to collect would finance the building’s operations out of pocket, then send one large bill after the books closed. Most retail and office leases do not work that way. They let the landlord bill an estimate each month so cash comes in as cash goes out.

The estimate is a forecast. Last year’s actuals are a common starting point because they already exist. A current-year budget is another. Neither is a promise. Snow that did not fall last year can fall this year. A vacant bay can lease and change occupancy. An insurance renewal can move. The true-up exists because the forecast and the year will not match exactly.

That is also why a low monthly estimate is not a gift. If the landlord billed too little, the shortfall arrives as a true-up invoice — often in the first quarter, when cash-flow surprise is least convenient. A high estimate is not automatically overreaching; it may simply be conservative. The test is the year-end pool and the lease, not the monthly amount by itself.

Some leases let the landlord revise the estimate mid-year if costs are running ahead. Some do not. If a revised estimate arrives, treat it as a new installment schedule, not as a settlement. The settlement still happens after year-end.

When the letter usually arrives

Leases typically require the landlord to deliver the annual statement within a set number of days after the CAM year ends. Calendar-year buildings often produce packets in the first quarter — January through March — once vendor invoices are in, occupancy is certified, and the general ledger is closed enough to print. That is a description of common timing, not a rule. Some landlords run later. Some buildings are on a fiscal year that is not the calendar year; a June 30 year-end moves the usual window into late summer. A newly acquired property can be late because the books changed hands.

The deadline, and what happens if the landlord misses it, is in your lease. Some forms say a late statement waives the landlord’s right to collect a shortfall. Some say the tenant still owes, but the objection clock does not start until delivery. Some are silent. Do not assume a market custom. Read the clause, or ask counsel.

Delivery also starts a clock that runs the other way. Many leases give the tenant a limited number of days to object or to request books and records. Missing that window can waive a challenge even if the math is wrong. That is why the first move, before debating a line item, is to find the date of the letter and the objection paragraph. The reconciliation chapter starts there.

The one formula

In its simplest form the settlement is one line:

(recoverable pool × pro-rata) − estimates paid = true-up

• Pro-rata is usually tenant square feet divided by building GLA (gross leasable area). Some leases use rentable area. Some freeze a stipulated denominator that does not shrink when space goes vacant. Some exclude a major or a pad that does not participate. Enter whatever the lease names as the denominator. There is no market “standard CAM percentage.” Your share is the fraction the lease writes down.
• Recoverable pool is not “all building costs.” It is the expenses the lease lets the landlord pass through, after exclusions, and after any gross-up, admin / management fee, and controllable cap the lease describes. Those adjustments change the pool before your pro-rata is applied. The simple formula above is the headline. The reconciliation walkthrough is how the pool is built.
• Estimates paid are the monthly or quarterly CAM installments you already remitted for that year. Match them to your cash or AP records, not only to the landlord’s cover letter. A missing month on their side, or a mid-year estimate change on yours, will move the true-up even if the pool is right.

A positive result is an amount due from the tenant. A negative result is a credit — usually against later estimates, less often a refund. The sign does not tell you whether the pool is correct. It only tells you the direction of the settlement the landlord computed.

Worked EXAMPLE — the homepage sample

The numbers below are the labeled sample on the homepage calculator. They are an example so you can reproduce the arithmetic. They are not a real building and not a recommended rate.

Positive, credit, and a near-zero settlement

Positive. The landlord says you underpaid. The letter will often attach an invoice payable in a stated number of days. Paying it is not the same as agreeing the pool. If the lease gives you a review period, that period is usually still running. Some tenants pay under reservation of rights; whether that preserves a challenge is a lease-and-counsel question, not something this site decides.

Credit. The landlord says you overpaid. Credits are commonly applied to the next months’ estimates. A cash refund is less common and is sometimes limited to tenants who have left the building. If the credit is large relative to monthly estimates, ask how it will be applied so it does not sit unused while you keep paying the old estimate.

Near zero. “Settled” can mean the estimates were close. A $40 difference on a $35,700 allocation is a rounding story, not a reason to skip the statement. The pool can still contain a line that does not belong. A near-zero true-up tells you the forecast matched the landlord’s actuals. It does not tell you the actuals match the lease.

Watch the estimates figure as carefully as the pool. If you paid $32,000 and the statement subtracts $28,000, the true-up is $4,000 larger than it should be before you have looked at a single cost line. Reconcile cash first. It is faster than reconciling landscaping invoices.

What the letter is not

The statement is the landlord’s version of the math. It is not a judgment. It is not a finding by a court, an accountant you hired, or an auditor. It is not automatically due before the review period the lease gives you. It is not proof that every line in the pool is recoverable. A cost that is on the statement can still be excluded by the lease.

It is also not a complete set of books. Most packets are a cover letter plus a one- or two-page rollup. The rollup is a summary. The backup — general ledger, invoices, occupancy support, fee calculation, prior-year controllable — is how you test it. You do not need every invoice on the day the letter arrives. You do need to know what to ask for, and when the asking window closes. That list lives in the reconciliation chapter.

Finally, the letter is not a “standard CAM %” of rent or of sales. This site will not invent one. Your share is the fraction and the definition in the lease. If someone tells you CAM “should be” a certain percent of sales, they are quoting a rule of thumb that is not in your contract. Ignore it for settlement purposes.

Where to go next

If you only needed the definition, you have it: monthly estimates versus the recoverable pool; positive means you owe; negative is a credit. If you have the statement in hand, go to how to read a CAM reconciliation and walk the denominator, the pool, gross-up, fee, cap, and backup. If the packet is labeled operating expenses or additional rent, use operating-expense pass-throughs. If tax and insurance are in the same envelope, use NNN true-up. Mark questioned costs on the exclusions checklist.

The free calculator on the homepage reconstructs the usual sequence from the figures on the letter. The optional $79 landlord packet is a two-page worksheet — line-item math plus a blank exclusion checklist — not an audit and not a subscription. Neither replaces reading the lease.