Common-area-maintenance reconciliation is one of the most technically demanding tasks in commercial property accounting — and also one of the most consistently done wrong. The reason isn't complexity for its own sake. It's that the process requires three separate calculations to agree with each other at the same time: the CAM pool, the tenant's proportionate share, and any caps or exclusions the lease specifies.
The CAM pool is where most errors start. Not every operating expense is recoverable under every lease, and the list of allowable costs changes from lease to lease even within the same building. Admin fees, capital improvements, management fees — each has different treatment in different documents. Building the pool without doing a line-by-line lease review first means starting with the wrong number.
Base years add a second layer of complexity. Triple-net leases that include a base year provision compare actual expenses in the reconciliation period against a baseline year, and tenants only pay for increases above that baseline. If the base year figures are stale or were set incorrectly at lease signing, every subsequent reconciliation will be off — and the error compounds annually.
Expense caps are the third variable. Many leases cap annual CAM increases at a fixed percentage, regardless of actual cost increases. Tracking these correctly requires maintaining a running cap balance for each tenant, not just recalculating from scratch each year.
Getting a CAM reconciliation right means building the pool from lease documents, not from the GL alone, and maintaining a reconciliation workpaper that carries forward prior-year figures and cap balances as a matter of process, not a one-off calculation.
