CAM reconciliation, done properly.

Updated October 3, 2026 · DF Property Management

What CAM is — and isn't

Common area maintenance (CAM) covers the cost of running the parts of a property that all tenants share: parking lots, walkways, landscaping, common hydro and lighting, snow and ice control, garbage, shared HVAC, fire and life-safety testing, security, and the management that coordinates it all. In most net leases, realty taxes and building insurance are recovered alongside CAM as separate lines of additional rent.

What's in and what's out is set by each lease, not by custom. Before you build a budget, read the operating-cost definition and the exclusions in every lease in the property. In older plazas, you'll often find three or four different versions.

The annual cycle

1. Build the budget (before January). Start from last year's actuals, adjust for known contracts — snow, landscaping, waste — and expected increases in insurance and taxes. Separate operating items from any capital work you intend to amortize.
2. Allocate and bill estimates. Calculate each tenant's share and bill one-twelfth monthly with base rent. Send each tenant a short budget summary; tenants who understand the number argue less about it.
3. Track actuals all year. Code every invoice to a CAM category as it's paid. A reconciliation built from a year of clean coding takes days; one built from a shoebox takes weeks.
4. Close the year. Once the last invoices and the final tax bill are in, total actual recoverable costs by category, apply exclusions, gross-up and caps.
5. Issue reconciliation statements. Each tenant gets a statement showing its share of actual costs, what it paid in estimates, and the balance owing or credit due. Most leases set a deadline for this — often within a few months of year-end. Missing it can weaken or waive your right to collect.
6. Collect or credit, then reset. Bill balances owing, apply credits to the next month's rent, and use the actuals to set next year's estimates.

Proportionate share

The default formula is the tenant's rentable area divided by the total rentable area of the property. Three things complicate it:

• Anchor or pad tenants who pay their own costs (a freestanding bank or fast-food pad, for example) and are excluded from some pools.
• Negotiated caps on a tenant's annual increase in controllable costs. The landlord absorbs the excess — not the other tenants, unless their leases allow it.
• Separate cost pools — for instance, an elevator or interior corridor that only the second-floor offices use. Allocate those to the tenants who benefit, if the leases permit.

Gross-up, explained

Some costs rise and fall with occupancy: janitorial in common areas, a share of utilities, waste. If a building is 75% leased and these costs are divided over the leased area only, tenants pay for vacant space. If they're divided over the whole building, the landlord absorbs costs it may be entitled to recover.

A gross-up clause adjusts variable costs to what they would have been at a stated occupancy — commonly 95% or 100% — and then allocates them. It should only apply to costs that genuinely vary with occupancy. Grossing up fixed costs such as insurance or realty taxes is a classic audit finding.

Admin and management fees

Most net leases allow the landlord to charge an administration fee on top of operating costs — often expressed as a percentage of CAM, and commonly somewhere in the 10–15% range in the GTA, though the lease governs. Watch for:

• Charging the admin fee on realty taxes or insurance when the lease limits it to operating costs.
• Charging both an admin fee and a separate management fee where the lease allows only one.
• Charging the fee on amortized capital items when the lease excludes them from the fee base.

Realty taxes

For multi-tenant properties assessed as one roll number, taxes are usually allocated by area. If units are separately assessed, each tenant pays its own unit's tax. Either way, keep in mind that MPAC reassessments and appeals can change the bill after the fact. If you win an appeal, most leases require you to refund the tenants' share of the reduction — budget for that and keep the paperwork.

Snow — the line item that breaks budgets

In a GTA plaza, winter control is often the largest controllable CAM cost. Seasonal (fixed-price) contracts make the budget predictable; per-event or per-hour contracts can be cheaper in a mild winter and very expensive in a heavy one. Whichever you use, keep the contractor's logs: they support the reconciliation and your defence if someone slips. Our retail plaza management guide covers the liability side.

Capital items and reserves

Parking lot resurfacing, roof replacement and rooftop units are the expensive surprises. Many net leases let landlords recover capital costs only by amortizing them over their useful life, sometimes with interest, and sometimes only if the work replaces worn components or reduces operating costs. Some leases allow a reserve fund contribution instead. Whatever your leases permit, show capital items as a separate line on the reconciliation, with the amortization schedule, so tenants can follow the logic from year to year.

Tenant audits

Many leases give tenants the right to audit operating costs within a set period after receiving the statement. When a tenant exercises it:

1. Check the lease. Confirm the audit window, who may perform it (some leases exclude contingency-fee auditors) and who pays if the overcharge exceeds a threshold.
2. Provide organized records. General ledger by CAM category, invoices, contracts, the allocation schedule and gross-up calculation.
3. Respond on substance. Accept clear errors quickly and credit them. Dispute the rest in writing with references to the lease clause.
4. Fix the process. An audit finding in one lease usually applies to others in the building. Correct it for everyone.

HST on recoveries

If the landlord is an HST registrant, CAM and tax recoveries billed to commercial tenants are part of the rent and generally attract HST at 13%. See HST on commercial rent in Ontario.

How we handle it

On properties we manage under our commercial property management service, every invoice is coded to a recovery category when it's paid, and owners see recoverable costs on the monthly statement with invoices attached. At year-end the reconciliation is already mostly built. For the basics of how leases split costs, start with gross vs net vs triple-net leases.

General information, not legal or tax advice. Your leases govern what can be recovered; have them reviewed if they're unclear.