Property Tax Pass-Through in Commercial Leases: NNN, Timing, and Protest Rights

Property tax pass-throughs look like the simple part of a commercial lease reconciliation. The bill arrives, you split it by pro-rata share, and you're done. In practice, property tax reconciliation generates more disputes than almost any other CAM category — because the timing is complex, the amounts are large, and protest rights create variables that most landlords handle inconsistently.

How Property Tax Pass-Throughs Work

In a NNN lease, the tenant is responsible for their allocable share of property taxes assessed on the property. The landlord collects the taxes (either through monthly estimates rolled into CAM or as a separate tax escrow), pays the taxing authority, and then reconciles the actual bill against what the tenant paid.

The mechanics:

1. At the start of each year, the landlord estimates the current year's tax bill — either based on the prior year's actual bill or a projection if values are rising.
2. The tenant pays monthly estimates (e.g., 1/12 of the annual estimate per month) as part of their monthly CAM payment.
3. When the actual tax bill arrives — which may be a single annual bill, semi-annual installments, or quarterly payments depending on jurisdiction — the landlord pays it.
4. The annual reconciliation compares actual taxes paid to estimates collected and settles the difference.

This is straightforward when tax bills are predictable. It gets complicated during reassessment years, protest proceedings, and when supplemental bills arrive outside the normal cycle.

The Reconciliation Timing Problem

Property taxes don't always align neatly with calendar-year CAM reconciliations. This creates timing disputes that both landlords and tenants mishandle.

Example: A Texas county sends property tax bills in November for the current calendar year, due by January 31 of the following year. A landlord on a December 31 fiscal year receives the November bill, pays it in January, and includes it in the Q1 payment. Which CAM year does it belong to?

Most leases say taxes are charged in the year they're assessed or levied, not the year they're paid. Under that reading, the November tax bill belongs in the current calendar year reconciliation even if payment doesn't occur until January. Landlords who charge it in the payment year instead are potentially double-dipping — collecting estimates for the bill in Year 1 but not crediting it until Year 2.

This problem is compounded in jurisdictions with fiscal years that don't match the calendar. California property taxes run July 1 to June 30. A tenant on a calendar-year lease is always getting taxes from two different fiscal years in a single reconciliation. The allocation methodology should be stated in the lease or established by clear practice — and it should be consistent year over year.

Property Tax Protests and Their Effect on CAM

When a landlord protests a property tax assessment and wins, the assessed value decreases and the tax bill is reduced. If taxes are passed through on an actual-cost basis, the savings flow back to tenants in proportion to their pro-rata share.

Here's a worked example: A 200,000 SF office building has a tax bill of $1,100,000. The landlord protests and secures a reduction, bringing the bill to $940,000. A tenant occupying 22,000 SF (11% pro-rata) was estimated and billed $121,000 for the year. The final bill is $103,400. The tenant gets a $17,600 credit in the reconciliation.

The complication: Protests take time. A protest filed for Tax Year 2024 might not be resolved until late 2025 or even 2026. Many leases address this with language like: "If property taxes for any tax year are paid based on an estimated or unresolved assessment, the reconciliation for that year shall be subject to adjustment upon final determination of the tax liability."

If your lease has this language, you need to track which reconciliation years have open protests and hold the final reconciliation until the protest resolves — or issue a preliminary reconciliation with an explicit caveat that the tax line is subject to adjustment.

Landlords who don't track protest status and issue final reconciliations while protests are pending either over-collect (if the protest succeeds) or have to reopen closed reconciliations later — both create tenant relations and accounting headaches.

Who Controls the Protest Decision

Most NNN leases give the landlord sole discretion to pursue or not pursue property tax protests. Some leases require the landlord to pursue protests when the potential savings exceed a threshold. Others give the tenant the right to require a protest at the tenant's expense.

Tenant-favorable language looks like this: "Upon Tenant's written request, Landlord shall promptly initiate proceedings to contest any real property tax assessment that Tenant reasonably believes is excessive. The cost of such proceedings shall be included in Operating Expenses only to the extent such proceedings result in a reduction of Taxes."

Landlord-favorable language: "Landlord shall have the sole and absolute right to contest, protest, or seek reduction of any property tax assessment in such manner as Landlord, in its reasonable business judgment, deems appropriate."

If your lease is silent on protests, the landlord has implied discretion to decide — but may face scrutiny from sophisticated tenants who notice that comparable properties in the market have successfully protested while theirs hasn't.

Supplemental Tax Bills

Supplemental bills are one-time assessments triggered by a change in property ownership that causes a reassessment. In California (where Prop 13 caps reassessments to 2% annual increases until sale), a property sale triggers immediate reassessment to market value. The "supplemental" bill covers the difference between old and new assessed values for the period from the sale date through the end of the fiscal year.

These bills can be substantial. A $15M to $28M sale in Los Angeles might generate a supplemental bill of $168,000 for the stub period. The question of who pays — and in which reconciliation year — is often contested.

The landlord argument: The supplemental bill relates to the current year's assessment; it goes in the current year's CAM.

The tenant argument: The supplemental bill is a consequence of the ownership change — a landlord-caused event — and shouldn't be passed through at all.

What the lease typically says: Most well-drafted NNN leases include supplemental bills in the definition of "taxes" without restriction, meaning they pass through like any other tax bill. Tenant-favorable leases sometimes exclude "taxes attributable to a change in ownership or refinancing of the property." If your lease has this exclusion, supplemental bills from a sale are not passable.

For multi-tenant properties, supplemental bills are allocated on the same pro-rata basis as regular taxes. The timing question — which year — should follow the accrual principle: charge to the period being assessed.

Property Taxes in Modified-Gross Leases

In a modified-gross lease with a tax expense stop or base year structure, the tenant's tax exposure is limited to increases above the base year amount. This is fundamentally different from NNN — the tenant doesn't share in the full tax burden, only the upside.

How it works:

• Base year taxes: $185,000 total (2023 lease year)
• Year 3 taxes: $214,000
• Increase over base: $29,000
• Tenant's pro-rata share (18%): $5,220 pass-through

If the landlord successfully protests in Year 3 and the final bill is $197,000, the pass-through drops to $12,000 total, and the tenant's share falls to $2,160. The tenant's estimates for Year 3 were based on $29,000 in pass-through; the reconciliation results in a $5,220 - $2,160 = $3,060 credit.

Base year selection matters enormously. A base year with an unusually high tax bill (year of assessment after a sale, for example) protects tenants from near-term increases. A base year with artificially low taxes (a protest year, or a year before a major reassessment) exposes tenants to large pass-throughs as values normalize. See our guide on 2026 property tax increases for what's happening in current markets.

What's Included in the Tax Definition

"Taxes" in a commercial lease is usually defined, not just implied. The definition determines what the landlord can pass through. Standard inclusions:

• Real property taxes and assessments on the land and improvements
• Special assessments (improvement districts, BIDs, special levy districts)
• Personal property taxes on landlord-owned personal property in common areas
• Fees paid to contest assessments (when protests are authorized)

Common exclusions from tenant-favorable definitions:

• Income, franchise, or profit taxes of the landlord
• Estate, inheritance, or gift taxes
• Excess profit or windfall profit taxes
• Transfer taxes arising from sale of the property
• Penalties and interest from the landlord's late payment of taxes

If your lease definition is narrow — say, "ad valorem real property taxes only" — then special assessments and BID levies may not be passable. Landlords who include them anyway without lease support are over-collecting.

Caps on Tax Pass-Throughs

Property taxes are almost universally classified as non-controllable expenses, which means they're typically excluded from controllable CAM caps. The logic is straightforward: the landlord can't control what the tax authority assesses.

But in strong tenant markets, some leases include aggregate limits on all operating expenses — controllable and non-controllable — or require landlord approval before passing through single-year tax spikes above a threshold. This is uncommon in standard retail and industrial leases but appears in major office tenant negotiations.

If you have a CAM cap that explicitly excludes taxes, that exclusion needs to be clearly stated in the reconciliation narrative. Tenants who receive reconciliations without clear cap methodology documentation routinely dispute which expenses were capped and which weren't.

Best Practice: Separate Tax Reconciliation

Given the complexity — timing issues, protests, supplemental bills, base year mechanics — the cleanest practice is to reconcile property taxes separately from operating expenses. Many institutional landlords do this as a matter of course: a single combined "CAM reconciliation" for operating costs, and a separate "Tax reconciliation" for real property taxes.

Separate reconciliation lets you:

• Track protest status and mark tax years as "pending" without holding up the operating expense reconciliation
• Issue tax reconciliations on a different schedule (after the final bill is received) without delaying CAM
• Show tenants clear year-over-year tax comparisons without blending them into operating expense trend data

For help streamlining your CAM and tax reconciliations, CapVeri automates the reconciliation workflow from GL export to tenant statement — including separate handling of tax line items with protest tracking. See our real estate tax reconciliation guide for the full methodology.