The CAM reconciliation lands in your inbox and something looks wrong. The number is higher than you expected. A line item does not match what your lease actually says. You are not sure if you are reading it correctly, or if your landlord is.
Here is the problem most tenants run into: the clock starts the moment you receive that statement.
Most commercial leases give tenants 30 to 90 days to dispute a CAM reconciliation. Some leases set an even shorter window. Miss it and the statement becomes final — the landlord can treat the billing as accepted. That is not a hypothetical. It is a clause that shows up in standard lease language, and it has been upheld in court.
So what do you actually do if you think your CAM charges are wrong? Here is the process, step by step.
40% of CAM reconciliations contain material errors (Tango Analytics, cited by PredictAP, 2023)
Step 1: Pull Your Lease and Find the CAM Provisions
Before you can dispute anything, you need the source document. Get your lease. Find the CAM or "Additional Rent" section — it usually appears under a heading like "Operating Expenses," "Common Area Maintenance," or "NNN Charges."
Read these sections specifically:
- What expenses are included. Your lease should list (or define by reference) what goes into the CAM pool. This is where most overcharges originate — expenses that belong to the landlord, or that were specifically excluded in negotiation, end up in the pool anyway.
- What expenses are excluded. Many leases carve out capital expenditures, leasing commissions, landlord overhead, and debt service. If the reconciliation includes line items that fall into these categories, that is a dispute.
- How your pro-rata share is calculated. The lease should define the numerator (your square footage) and denominator (the total square footage used for the calculation). Both can be wrong.
- The CAM cap, if you have one. A cap limits how much CAM can increase year over year. If your lease has a cap and the increase exceeds it, the landlord has overbilled you regardless of what the underlying expenses were.
- The audit rights clause. This tells you how long you have to dispute and whether you have the right to review supporting documentation.
Write down the specific language. You will reference it when you write your dispute letter.
Step 2: Identify the Discrepancy
Now compare the reconciliation statement to your lease line by line.
You are looking for four types of problems:
1. Included expenses that your lease excludes. Common examples: roof replacement or HVAC system replacement (capital expenditures, not maintenance), leasing agent commissions for filling vacant spaces, management fees above the cap your lease sets, or executive salaries passed through as overhead.
2. A math error in your pro-rata share. Take your square footage and divide it by the denominator your landlord used. Does it match your lease? Landlords sometimes use the wrong denominator — either a smaller number than the actual rentable square footage (which inflates your share) or a number that does not account for occupancy exclusions your lease requires.
3. A gross-up that went too far. Some leases allow landlords to gross up variable expenses to a hypothetical 90% or 95% occupancy when the building is underoccupied. This is legitimate in theory. In practice, landlords sometimes apply the gross-up to fixed expenses (which do not scale with occupancy), or they gross up the full expense pool rather than just the variable portion.
4. A base year that changed without notice. If your lease uses a base year for expense comparisons, the reconciliation should use the same base year established at signing. If it has shifted — or if the landlord adjusted the base year expenses downward — your comparison will be off.
If you find any of these, document exactly what you found: which line item, what the lease says about it, and what the reconciliation shows.
Step 3: Calculate the Overcharge
Put numbers on it. Vague disputes ("I think this is too high") go nowhere. Specific disputes ("your management fee calculation applied a 6% rate; my lease caps it at 4%, resulting in a $2,840 overcharge") get resolved.
For each discrepancy you identified:
- Find the dollar amount in the reconciliation.
- Calculate what the correct amount should be under your lease terms.
- Compute the difference.
Add up all the differences. That is your claimed overcharge. Keep your arithmetic visible — show the landlord exactly how you got the number. If they cannot point to a specific flaw in your calculation, they have to address it.
This step is where most tenants give up because the math gets complicated. Management fee overcharges require reading the fee basis definition (gross revenues vs. total expenses vs. net CAM pool — each gives a different result). Pro-rata share errors require knowing the correct denominator. CAM cap violations require reconstructing the prior year's gross CAM and applying the annual increase limit.
That is the core problem I built CAMAudit to solve. Upload the lease and the reconciliation, and the tool runs all 14 detection checks automatically — including the math — in under 15 minutes.
Step 4: Gather Your Documentation
Before you send anything, assemble your evidence packet:
- The reconciliation statement from the landlord
- The relevant sections of your lease (pages with CAM provisions, definitions, any exhibits listing included/excluded expenses)
- Your calculations showing the discrepancy
- Any prior-year reconciliations if your dispute involves a base year comparison or a CAM cap calculation that spans multiple years
- Your original lease execution date, lease term, and any amendments
If your lease gives you the right to audit supporting documentation, now is the time to exercise it. A formal audit request should go out at the same time as your dispute letter, or shortly before. You want the landlord on record as either providing or refusing to provide backup documentation.
Step 5: Send a Formal Dispute Letter
Do not dispute CAM charges verbally. Do not use email as your only channel if your lease requires written notice. Do not let the conversation live in a text thread with your building manager.
A formal dispute letter draft does several things:
- Creates a paper trail with a clear date, establishing that you disputed within the required window
- States your position specifically, with lease section references and dollar amounts
- Puts the landlord in the position of having to respond in writing
- Sets the stage for negotiation or, if necessary, arbitration or litigation
Your dispute letter should include:
- The date of your letter and the date you received the reconciliation
- The lease section that gives you the right to dispute
- A specific description of each discrepancy (what line item, what the lease says, what the statement shows)
- Your calculated overcharge for each item and the total
- A request for the landlord to provide a corrected reconciliation or to schedule a meeting to review the discrepancy
- If applicable, a concurrent request to exercise your audit rights
Keep the tone factual. This is not the moment for frustration. A letter that reads like a contract dispute — not a complaint — will get handled like a contract dispute.
One important warning: do not withhold rent as leverage. In most commercial leases, CAM charges are classified as "Additional Rent." Withholding Additional Rent is a lease default, which means the landlord can pursue termination remedies against you even if your underlying CAM dispute is valid. The dispute letter is the right mechanism. Let the dispute process work.
What Happens After You Send the Letter
A few things can happen:
The landlord agrees and issues a corrected statement. This is the best outcome. If they agree to a credit or reduction, get it in writing before the next payment cycle.
The landlord disagrees and explains why. Read their response carefully. They may have a legitimate basis you missed — a lease amendment you forgot about, a definition that covers the expense you thought was excluded. Reassess your position with that information.
The landlord ignores the letter or stonewalls. Follow up in writing, referencing your original letter. If the dispute amount is significant, this is when you bring in a tenant-side attorney or a forensic CAM auditor to escalate.
The parties negotiate a settlement. Many CAM disputes resolve through negotiation — landlords often prefer to reduce a bill by a few thousand dollars rather than go through a formal audit process. Your documented position gives you leverage in that conversation.
The audit rights clause in your lease is your most important tool here. If you formally request documentation and the landlord cannot produce it, that gap strengthens your position considerably.
FAQ
Can I dispute a CAM charge after the lease ends?
Sometimes. Most jurisdictions have a general contract statute of limitations — often four to six years depending on the state — that applies to overcharge claims. The discovery rule in some states means the clock starts when you discovered (or should have discovered) the error, not when the reconciliation was issued. A tenant-side attorney can tell you what applies in your state. That said, acting during the active lease is almost always easier than pursuing it post-termination.
Do I need a lawyer to dispute CAM charges?
Not always. If the discrepancy is clear-cut and well-documented — a management fee above the contractual cap, for example — a well-written dispute letter from you can resolve it. For large discrepancies, complex gross-up violations, or landlords who refuse to engage, a tenant-side attorney with commercial lease experience is worth the cost.
What if my lease has an arbitration clause?
Many commercial leases require arbitration before litigation for billing disputes. Read your dispute resolution provision carefully. If arbitration is required, your dispute letter becomes the first step in that process — and you may have specific timelines and notice requirements to follow. Missing the arbitration trigger date can affect your ability to pursue the claim.