Office Property Bookkeeping: CAM, CapEx, and Chart of Accounts

September 2026  ·  CleanCRE

Office buildings run on fewer, bigger relationships than multifamily. Instead of dozens of leases and monthly turnover, you've usually got a handful of tenants on long-term leases, each with its own terms for rent escalations, CAM reimbursement, and who pays for what. The bookkeeping reflects that: less volume, but each line item carries more weight, and getting one lease's terms wrong can cost real money.

Here's what the work actually covers.

CAM Reconciliation Is The Center Of Gravity

Common area maintenance, landscaping, cleaning, shared utilities, security, gets pooled and then billed back to tenants based on their share of the building, usually by square footage. That math only comes out right if the expenses feeding the pool were classified correctly all year. Miscode a repair that should've gone to CAM, or fail to separate a cost that should've stayed with the landlord, and the annual reconciliation either shorts the ownership or overbills a tenant. Either direction turns into a dispute, and disputes over CAM charges are some of the most common conflicts between office landlords and tenants.

CapEx Has To Live Somewhere Different Than Repairs

Office buildings carry big, infrequent capital costs, roof replacement, elevator modernization, HVAC overhauls, that are fundamentally different from routine maintenance even though both can look like "building expenses" on the surface. A repair that keeps the building running gets deducted in the year it happens. A capital improvement that adds value or extends the building's life gets capitalized and depreciated over time instead. Mixing these up doesn't just mess up this year's numbers, it changes depreciation schedules for years afterward, and it's one of the more common mistakes that surfaces when a CPA reviews the books at tax time.

Loan Payments Aren't One Number

A single mortgage payment is actually three different things happening at once: principal, which reduces a liability and isn't an expense at all, interest, which is a real expense that belongs on the income statement, and escrow, which usually covers property taxes and insurance and shouldn't hit the P&L until the tax bill or premium is actually paid. Recording the whole payment as one expense overstates operating costs and makes the building look less profitable than it actually is.

Tenant Deposits And Escrows Stay Separate, Always

Security deposits and any tenant escrow funds are liabilities, not income, and they need to sit in their own account, separate from operating cash. This isn't optional in most states, and it's usually one of the first things checked if a dispute or an audit comes up. A deposit that gets treated as revenue on the books, even by accident, is a real compliance problem, not just a bookkeeping shortcut.

A Chart Of Accounts Built For How Office Actually Works

A generic chart of accounts treats "rental income" as one line and "maintenance" as another. Office needs more structure than that: base rent separated from CAM reimbursement income, late fees tracked on their own, and expenses split cleanly between operations (things that keep the building running day to day) and capital (things that go on the balance sheet and depreciate). Each tenant's lease terms are different enough that the categories need to hold up across all of them without collapsing into one vague bucket.

What Good Actually Looks Like

• CAM pool expenses classified correctly as they're incurred, not sorted out once a year at reconciliation time
• Capital improvements and routine repairs tracked in separate categories from day one, with documentation to back up the classification
• Mortgage payments split into principal, interest, and escrow every month, not booked as a single lump expense
• Security deposits and tenant escrows held in accounts completely separate from operating cash
• A chart of accounts that separates rent, CAM reimbursement, and other income instead of lumping it all together
• Monthly reconciliation of every account, not a scramble at year-end

Frequently Asked Questions

Why does CAM reconciliation cause so many disputes?

Because it depends entirely on the expense coding behind it. If shared costs get classified inconsistently during the year, the annual reconciliation comes out wrong before anyone even starts the math, and that usually surfaces as a tenant questioning their bill.

What's the actual difference between a repair and a capital improvement?

A repair keeps the building operating the way it already does and gets deducted the year it happens. A capital improvement adds value or extends the building's useful life, a new roof, an elevator overhaul, and has to be capitalized and depreciated instead of expensed immediately.

Why does it matter how a mortgage payment gets recorded?

Because only the interest portion is actually an expense. Recording the full payment as one expense overstates costs and makes the property look less profitable than the real numbers show.

Do security deposits count as income?

No. They're a liability until specific lease conditions are met, and they need to sit in a separate account from operating funds, not appear on the income statement as revenue.