Overview
If you manage commercial properties, CAM (Common Area Maintenance) charges are part of your daily life. Tenants pay their share of building operating expenses — things like property taxes, insurance, landscaping, and common area upkeep — on top of base rent. But managing the full lifecycle of CAM charges, from setup to year-end reconciliation, involves several moving parts.
This guide walks you through the entire CAM process in DoorLoop: how to structure your leases, set up allocations, charge tenants monthly, and reconcile actual expenses at year-end. Whether you're managing a strip mall, office building, or mixed-use property, you'll find everything you need here.
What Are CAM Charges?
CAM stands for Common Area Maintenance — the operating expenses a landlord incurs to run a commercial property. These are often passed through to tenants under a triple net (NNN) or modified gross lease structure.
Common CAM expenses include:
Common area cleaning and maintenance
Landscaping and snow removal
Property insurance
Property taxes
Security
Repairs and maintenance
Common area utilities
Management fees
Each tenant's share is typically based on pro-rata square footage — the percentage of the building they occupy. Some leases use different methods (even splits, fixed amounts, or negotiated percentages), but square footage is the most common.
The CAM Lifecycle: 5 Steps
Here's the full process from lease signing to year-end reconciliation. DoorLoop supports every step.
The 5 Steps at a Glance
Set up the lease with CAM terms
Define how expenses are allocated across tenants
Charge tenants estimated CAM monthly
Track actual expenses throughout the year (automatic via your P&L)
Reconcile and true-up at year-end
Step 1: Set Up the Lease
When creating a commercial lease with CAM charges, you have two options for how to record the NNN/CAM charges:
Include CAM as line items in the recurring rent charge — Best when the estimated amounts are fixed each month. Add insurance, taxes, and CAM as separate line items within the recurring rent schedule.
Add CAM as separate recurring charges — Best when you want to track CAM charges independently from base rent, or when CAM is billed on a different schedule.
Detailed guide: Record a Triple Net Lease (NNN) — covers both methods with step-by-step instructions.
Step 2: Set Up Custom Allocations
If CAM expenses are shared across multiple tenants (the most common scenario), you'll want to define how those expenses are split. DoorLoop lets you create custom allocation presets on each property with three methods:
Method | How It Works | Best For |
Allocate by Size | Each tenant's share is proportional to their unit's square footage | Most commercial properties — the industry standard |
Allocate Evenly | Each tenant pays an equal share regardless of unit size | Properties where all units are similar size, or where the lease specifies equal splits |
Allocate Manually | You set the exact percentage for each unit | Complex leases with negotiated shares that don't follow a standard formula |
For both "Allocate Evenly" and "Allocate by Size," you can choose whether to include or exclude vacant units from the calculation.
Detailed guide: Set Up Custom Allocations for CAM Charges and Credits — walks through the full setup with screenshots.
Step 3: Charge Tenants Monthly
Throughout the year, tenants pay estimated CAM charges based on your budget or prior year actuals. There are two ways to post these charges:
Recurring charges — Set up a recurring charge on each lease for the estimated monthly CAM amount. This is the simplest approach when estimates are the same each month.
Bulk charges — Use DoorLoop's bulk charges feature with your custom allocation presets to post charges across all leases at once. This is faster for properties with many tenants and is especially useful when CAM amounts vary month to month.
Tip: Whichever method you choose, post your CAM charges to a revenue account specifically designated for CAM (e.g., "CAM Income" or "Operating Expense Recoveries"). This makes it easy to track how much you've collected vs. how much you've actually spent.
Step 4: Track Actual Expenses
This step happens automatically. As you pay bills, record expenses, and process invoices throughout the year, those costs flow into your Profit & Loss report under the appropriate expense accounts. There's nothing extra to do — just manage your books as you normally would.
At year-end, the CAM Reconciliation Report will pull these actual expense totals directly from your P&L.
Step 5: Reconcile at Year-End
This is where it all comes together. The CAM Reconciliation Report compares what each tenant actually owes (based on real expenses) against what they've already paid in estimated CAM charges throughout the year.
The report calculates:
Each tenant's pro-rata share of every recoverable expense account
Any per-lease adjustments (account exclusions, admin fees, base year stops, fixed CAM amounts)
The true-up — the difference between what the tenant owes and what they've already paid
When reconciliation is complete, you can:
Export tenant statement PDFs — Professional statements showing the full breakdown, ready to send to tenants
Download an Excel worksheet — For your records or to share with property owners
Post true-up charges or credits — Apply the difference to each tenant's lease
Detailed guide: Run a CAM Reconciliation Report — full walkthrough of the report including setup, reading results, per-lease customizations, and exporting.
Common Scenarios
Strip Mall with 5 Tenants, All NNN
Set up each lease with base rent + estimated CAM line items. Create a "by size" allocation on the property. Post monthly CAM charges via bulk charges. At year-end, run the CAM Reconciliation Report, review the expense pool, and export tenant statements.
Office Building with Mixed Lease Types
Some tenants are NNN, some are modified gross (they pay a portion of CAM), and one anchor tenant has a fixed CAM amount. Set up each lease according to its terms. In the CAM Reconciliation Report, use the per-lease settings drawer to:
Set modified gross tenants to exclude certain expense accounts
Set the anchor tenant to "Fixed" lease type with their annual CAM amount
Add admin fees where the lease allows it
Property with Base Year Stops
Some leases specify a base year amount for certain expenses — the tenant only pays their share of expenses above that base. In the CAM Reconciliation Report's per-lease settings, set a base amount for each relevant expense account. The report will automatically calculate only the amount above the base.
Building with Vacant Units
When setting up the CAM Reconciliation Report, choose your pro-rata basis:
Total Rentable SF — You (the landlord) absorb the vacant portion of CAM costs
Occupied SF Only — Existing tenants cover the full expense pool
Check your lease language — most leases specify which method applies. You can also use the gross-up feature for variable expenses (like utilities) that would be higher at full occupancy.
Frequently Asked Questions
How often should I run the CAM Reconciliation Report?
We recommend running it quarterly to catch large variances early, then finalizing at year-end. This way, you can adjust estimated charges mid-year if actual expenses are trending significantly higher or lower than expected.
What if a tenant's lease excludes certain expenses?
Use the per-lease settings in the CAM Reconciliation Report to uncheck specific expense accounts for that tenant. Their share will only include the accounts you leave checked.
Can I add an admin/management fee on top of CAM?
Yes. In the per-lease settings drawer, enable the admin fee toggle and enter the percentage (commonly 10-15%). It's added on top of the tenant's calculated CAM share.
What happens after I reconcile?
Export tenant statements and send them to your tenants. For tenants who owe more, post a one-time charge to their lease. For tenants who overpaid, post a credit. Then update your monthly estimated charges for the coming year based on the current actuals.
Is the CAM report available on all plans?
The CAM Reconciliation Report is available in Reports. Note that Custom Allocations for CAM Charges (used for bulk charge posting) are not available on Starter Plans or Pro Plans — consider upgrading to Premium for that feature.
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Disclaimer
The information provided is not offered by a licensed accountant, should not be considered accounting, financial, or legal advice, and is provided (and intended) for general informational purposes only. Do not rely on the information provided; rather, please verify applicable accounting laws and regulations independently. This information should not be considered a substitute for professional advice and does not offer Generally Accepted Accounting Principles (GAAP). The author and publisher are not liable for any damages or losses resulting from reliance on this information.