A $14,200 invoice arrives in late January. The memo line reads "Building Improvement Assessment: 2025 Capital Project." The bookkeeper codes it to the CAM expense account with the usual monthly charges and moves on. For more context, see the landlord invoice coding guide for bookkeepers.
Six months later the controller asks why occupancy costs jumped 38% year over year. The answer sits in that January invoice. One question should have been asked when it arrived. Was this a one-time charge or a recurring one? And does the lease even allow it?
This question is bigger than how you label the charge. It sets how you code the expense. It sets how you explain it to the client. It tells you if the charge needs a close look before it lands in the budget for good.
Special Assessment: A one-time charge billed by a landlord outside the normal annual CAM reconciliation cycle, typically tied to a specific capital project, emergency repair, or retroactive cost recovery. Special assessments require explicit lease authorization to be collectible from the tenant.
Why the Distinction Gets Blurred
Landlord statements rarely use helpful labels. A statement might show twelve line items that all look like normal operating costs. The capital project charge might read "Common Area Maintenance: Q4 Supplement" or "Property Operating Expense: Special Allocation." You will not see the one-time nature of it. Not unless you read last year's reconciliation and compare each line.
Three types of charges cause the most confusion.
The first is capital project charges. A landlord replaces the building HVAC system and bills tenants for part of the cost. The lease decides the treatment. It may be an amortized recurring charge. It may be a one-time lump sum. It may not be allowed at all. Amortized means the cost is spread over the years the asset lasts. A $22,000 invoice coded as a routine repair is almost surely wrong.
The second is special assessments. The parking lot gets repaved. The lobby gets redone. The fire system gets upgraded. The landlord then sends an extra invoice for the tenant's pro-rata share. Pro-rata share is the tenant's slice of the cost based on its space. These are one-time charges tied to one event. They are not part of the yearly CAM pool.
The third is retroactive reconciliation adjustments. The landlord under-billed for two years. Now it sends a $6,400 true-up for that past period. A true-up corrects an earlier bill. This is real money owed. But it is not a cost for this year. Coding it as current CAM overstates this year and understates the past years.
The Lease Is the Governing Document
Before you code any landlord charge, ask one thing. What does the lease say? For one-time charges, two clauses matter most.
The CAM pool definition lists what the landlord may recover. Say it leaves out capital costs. Then a capital project invoice has no basis, no matter how big or needed the project. Say it allows amortized capital costs. Then the landlord should bill part of the cost over several years. Not a lump sum.
The exclusion list matters just as much. Most well-built leases leave out some items. They leave out leasing commissions and depreciation. They leave out costs to fix code problems that came before the tenant. They leave out costs paid by insurance. An invoice for any of these is more than one-time. It may not be owed at all.
A partner review found this exact issue on a retail client's reconciliation. The landlord billed a $9,800 "roof membrane replacement" as routine maintenance. The lease called any item lasting more than five years a capital cost. A roof membrane replacement clearly fits. The charge sat outside the allowed CAM pool. It should never have been billed.
Accounting Treatment: What Changes With the Classification
Recurring charges run through the standard occupancy expense account. You book them in the period they happen. Monthly CAM estimates are expensed as paid. Small reconciliation adjustments are expensed when billed.
One-time capital charges work best as prepaid expenses when the lease allows them. You then spread the cost over the period it covers. Say the landlord passes through an asset that lasts ten years. Expensing the full charge in one month makes the income statement wrong.
Retroactive adjustments belong to the past period they cover. Do not book them in the period the invoice arrives. A client on accrual basis may need a prior-period adjustment. If the amount is large, loop in the controller before the bill is paid. Not after.
Disputed charges should not be coded at all. Wait until the basis for the charge is clear. Paying a disputed invoice and coding it to expense can waive the client's right to contest it. Hold the payment in a suspense account during the lease review.
Building the Review Into the Workflow
The best way to catch one-time charges is simple. Compare this year's statement to last year, line by line. Flag any charge with no match in the prior year. This is not a lease audit. It takes thirty minutes with last year's reconciliation statement.
For a three-location retail client our tool processes, this check runs on its own. A line item surfaces when it is new. It also surfaces when it rises more than 20% year over year. The bookkeeper does not have to remember to compare. The check happens for them.
A new client may have no prior year to compare. Then ask the landlord for two years of reconciliation history before you code the first statement. This is a normal request. Most landlords will provide it.
The Client Conversation
When you find a one-time charge, the client talk has two parts. You explain what it is. You explain what happens next.
The first part is easy. A one-time charge is billed outside the regular yearly cycle. The lease may or may not allow it. It showed up on the statement. That alone does not mean the client must pay it without review.
The next step depends on the size of the charge and the lease language. Take a $1,400 extra billing with fuzzy lease terms. Often you code it as a current expense and note it in the file. Take a $14,200 capital project charge that the lease may not cover. Then pause payment. Request the backup. Review the CAM pool definition before the payment goes out.
The accounting team finds the question. It does not answer it. Telling the client a charge is or is not owed is a legal call, not an accounting one. Frame it this way. "This looks like a one-time capital charge. We need to confirm the lease allows the landlord to recover this before we pay."
Documentation
Document every one-time charge you look at. Put four things in the client file. Add the invoice. Add the lease language. Add the reason for the coding choice. If you flagged the charge for review, add the result.
This matters because one-time charges often come back. A landlord who bills a capital project charge one year may bill a like charge the next year. A documented prior review makes the next compare faster. It makes the client talk cleaner too.
It also helps if the client later runs a formal CAM audit. A clear pattern of one-time charges outside the CAM pool is strong evidence. It is just what an audit needs to build a recovery case.
This question is not busywork. It is the first filter in a CAM review. Get it wrong at the bookkeeping stage and every later step gets harder.