A listing says the net rent is $28 and the TMI is $14. That is not your rent per month. Here is what a net lease and a gross lease mean, what TMI covers, and how to turn the quote into a number you can budget. Checked October 4, 2026.
Net rent
Net rent, also called base rent or minimum rent, is what the landlord charges for the space itself. It is quoted in dollars per square foot per year, not per month.
What TMI covers
- T = Taxes: the property tax on the building, shared among the tenants.
- M = Maintenance: common-area costs such as snow removal, landscaping, the parking lot, cleaning and repairs, and often a property management fee.
- I = Insurance: the landlord’s insurance on the building. Your own business insurance is separate.
TMI is also called additional rent or CAM. Each tenant usually pays a share based on its area compared with the whole building. The landlord estimates it at the start of the year, then compares it with the real costs and bills or credits the difference.
Net lease, gross lease and semi-gross
- Net lease: you pay net rent plus your share of TMI. If taxes or maintenance go up, your TMI goes up.
- Gross lease: one rent that already includes the building’s costs. The landlord carries the risk that those costs rise, and usually prices that into the rent.
- Semi-gross: some costs are included and others are extra. Read exactly which ones.
A worked example
A 1,500 square foot unit at $30 net and $12 TMI, per square foot per year:
- Net rent: 1,500 × $30 = $45,000 a year, or $3,750 a month.
- TMI: 1,500 × $12 = $18,000 a year, or $1,500 a month.
- Total before HST: $5,250 a month.
- HST at 13%: $682.50 a month, so $5,932.50 a month with HST.
A commercial lease is a taxable supply, so HST applies to the rent. If your business is registered for GST/HST, you may be able to claim it back as an input tax credit. Ask your accountant.
Questions to ask about TMI
- What was the actual TMI for the last two years?
- When is the year-end reconciliation, and how is the difference paid?
- Is a management fee included, and how is it calculated?
- Are big repairs, such as a new roof or parking lot, charged through TMI?
- Is any part of TMI capped?
Run your own numbers with the commercial lease calculator. Next: how the square feet are measured.
Sources (official pages, checked October 4, 2026)
- CRA GST/HST Memorandum 19.4.1 – Commercial real property, sales and rentals (a commercial lease is a taxable supply)
- CRA – GST/HST rates (Ontario 13%)
- CRA – Input tax credits (rent for commercial activities)
- Ontario – Renting commercial property in Ontario (Commercial Tenancies Act, updated July 2, 2026)
Programs and limits change, often at budget time. Confirm the current rules on the official page before you rely on them.
Talk to me in English or Arabic: call or text (647) 465-3710, message me on WhatsApp, or email Mohieddinrealtor@gmail.com.
General information only – not financial, legal or mortgage advice. Please consult a licensed professional about your own situation.