TMI Explained: How to Negotiate Reconciliation and Audit Rights in a Commercial Lease in Ontario

In a commercial lease in Ontario, the base rent is only part of what you pay. In most industrial leases across the GTA, the rest is TMI: taxes, maintenance and insurance. The clauses that govern how TMI is estimated, reconciled and audited decide whether you pay what you owe or something more. This article explains how those clauses work and what to negotiate, whether you are signing a new lease or in a lease renewal negotiation. Understanding net lease vs gross lease is the starting point.

Net lease vs gross lease: where TMI comes from

In a gross lease, the tenant pays one rent figure and the landlord covers the building's operating costs. In a net lease, the tenant pays base rent plus a share of the costs of running the property. Most industrial leases along the 401, 407, 410 and 427 corridors are net leases, and many are called "triple net."

The difference matters because a net lease moves cost risk to you. Base rent is fixed by the lease. TMI is not. It changes with the property tax bill, the insurance market, snow removal, and the repair needs of the roof, paving and truck court.

TMI explained: what it covers

TMI, often called additional rent or CAM (common area maintenance) in other markets, usually has three parts:

• Taxes: municipal and education property taxes, plus any local improvement charges the lease allows.
• Maintenance: repairs, landscaping, snow clearing, lighting, management and administration, and shared services in a multi-tenant building.
• Insurance: the landlord's property and liability coverage for the building.

Your share is normally a fraction: the area of your premises divided by the area of the building or project. Every term in that calculation, including the denominator, is negotiable.

How TMI reconciliation works in an Ontario lease

Reconciliation is the year-end true-up. During the year, you pay monthly estimates based on a budget. After year-end, the landlord delivers a statement of actual costs. If the estimates were too low, you pay the difference. If they were too high, you receive a credit or refund.

For example, suppose you lease 20,000 square feet in a 100,000-square-foot building, so your share is 20%. Actual recoverable costs for the year come to $500,000, making your share $100,000. Your monthly estimates added up to $90,000, so you owe $10,000. Now suppose an audit shows that $60,000 of the $500,000 was a roof replacement the lease treats as a landlord capital cost. Your share of that error is 20%, or $12,000. That is more than the reconciliation payment, so the true position is a $2,000 credit in your favour.

The Commercial Tenancies Act sets some baseline rules for landlords and tenants in Ontario, but it does not regulate how TMI is calculated. The lease does. Leases also typically treat additional rent as "rent," so unpaid TMI can carry the same default consequences as unpaid base rent. Have your lawyer review these provisions closely.

What to negotiate in the reconciliation clause

Focus on the points that most often cause disputes:

1. Defined inclusions and exclusions. List what the landlord may not recover. Common exclusions are structural repairs, landlord financing costs, head-office overhead, leasing commissions, costs recovered from insurers or other tenants, and fines caused by the landlord.
2. Capital items. If a capital replacement is recoverable at all, ask that it be spread over its useful life, with only the annual portion charged to you.
3. Administration fee. Confirm the percentage, what it is charged on, and whether taxes are excluded from that base.
4. Proportionate share. Fix the area figures in the lease. Where gross-up for vacancy is allowed, limit it to costs that vary with occupancy.
5. Controllable cost caps. For a longer term, consider a cap on annual increases to costs the landlord controls. Taxes and insurance are usually excluded from caps.
6. Timing. Require the annual statement within a stated period after year-end, and limit back-billing for late or missed charges.
7. Tax appeals and refunds. Clarify who may appeal an assessment and how any refund is shared.

What to negotiate in the audit clause

An audit right is only useful if you can actually exercise it. Check these elements:

• Access to records. You or your accountant should be able to inspect the invoices and ledgers behind the statement, not just a summary.
• Window to dispute. Leases often make statements final if not challenged within a set period. Make sure the period is long enough to review and respond.
• Who may audit. Landlords often resist contingency-fee auditors. Agree on reasonable qualifications instead of a flat ban.
• Cost allocation. A common compromise is that the landlord pays for the audit if it finds an overcharge above a stated threshold.
• Refund and interest. Overpayments should be repaid promptly, ideally with interest, and credited at once if the lease has ended.
• Survival. The right should continue after expiry for the period it takes to finalize the last reconciliation.
• Paying under protest. Decide whether you must pay a disputed amount first. Withholding can risk a default, so most tenants prefer to pay and reserve their rights in writing.

Confidentiality is a fair request from landlords. Agree to it, with limits that do not prevent you from using the findings to enforce the lease.

Using the renewal to fix the clauses

A renewal is often the best moment to improve these terms, because both parties are already revisiting commercial lease terms. Before you start, review the last few years of statements and ask whether your audit window has closed. If a pattern of questionable charges appears, raise it early and ask that the renewal wording correct the definitions going forward. Owners benefit too. Clear, specific clauses mean fewer disputes and a smoother relationship over the term of an industrial lease in the GTA.

At Ghatan Commercial, Kam Ghatan has worked only in industrial, commercial and investment real estate for more than 25 years. He can help you understand how the cost provisions fit with your wider lease economics before you instruct your lawyer to finalize the document.

Frequently Asked Questions

What does TMI stand for in an Ontario commercial lease?

TMI stands for taxes, maintenance and insurance. It is the tenant's share of a property's operating costs in a net lease, paid in addition to base rent. The lease defines exactly which costs are included.

Can a tenant audit TMI charges in Ontario?

Only if the lease gives that right. Ontario law does not set a general audit right for commercial tenants, so it must be negotiated into the lease. A good clause covers access to records, a workable dispute window and a clear process for refunds.

Should I pay a disputed TMI reconciliation?

In most cases, speak to your lawyer first. Leases often treat additional rent as rent, so withholding payment can create a default risk. Many tenants pay the amount and give written notice that they reserve their right to dispute it, but the right approach depends on your lease wording.