Treadstone Associates
Case File № 731 · Rental & Investment

What the estoppel certificate caught

a Cobourg storefront-plus-apartments file the seller's own leases got wrong

A downtown Cobourg mixed-use purchase's ground-floor commercial tenant had quietly renegotiated its rent with the seller years before closing, and the seller's own lease copy never caught up. Only a signed estoppel certificate from the tenant itself -- not the paper lease -- confirmed what the unit actually pays, moving total debt service by a full six-tenths of a point.

OntarioUninsured · PurchaseFiled August 9, 20265 min read
$1,750/mo

the ground-floor tenant's real, current rent -- confirmed only by their own signed estoppel certificate

$450/mo

the gap between the seller's own stale lease copy and what the tenant actually pays

30.1%

total debt service on the estoppel-confirmed rent roll, against 29.5% on the seller's own paperwork

Anonymized illustration. The borrowers, dollar figures, and rates in this file are an illustrative composite — no real client is identifiable, and any rate shown is illustrative, not a quote. The rules are real: every regulatory figure is cited to its source in the Sources section, and the math computes exactly as shown.

№ 01

The client

A buyer purchasing a $520,000 mixed-use building in downtown Cobourg -- a ground-floor commercial unit under two residential apartments -- at 30% down, financed conventionally as an investment property mortgage.

Purchase price

$520,000, Cobourg

30% down, mixed-use investment purchase

Residential units

Two apartments at $1,450/mo each

Matches both the lease copies and each tenant's own estoppel certificate

Commercial tenant

$2,200/mo per the seller's lease copy

Actually paying $1,750/mo -- confirmed only by the tenant's own estoppel certificate

Buyer's own income

$9,200/month

№ 02

The problem

A commercial tenant's actual rent is only as reliable as the document proving it -- and the seller's own copy of the lease is not always that document.

What the seller's own paperwork missed

  • The seller's lease copy for the ground-floor commercial unit still showed the original $2,200/month rent
  • Years earlier, the tenant had negotiated a rent reduction directly with the seller that was never formalized in any written amendment the seller could produce
  • Nothing in the seller's own file proved what the tenant was actually paying today

The two residential leases upstairs matched exactly what their tenants confirmed, with no surprise at all. The ground-floor commercial lease did not.

№ 03

The numbers

Two very different total-debt-service figures come out of the same building, depending on which rent figure for the ground-floor unit the file actually relies on.

Qualifying on the estoppel-confirmed rent rollAmount
Purchase price$520,000
Down payment (30%)$156,000
Base mortgage$364,000
Total debt serviceOn the seller's stale lease copyOn the estoppel-confirmed rent
Qualifying payment (7.35%), 25 years$2,629/mo$2,629/mo
Property tax + heat$530$530
Rental income credited (50% add-back)$2,550$2,325
Car loan$310$310
Total debt service29.5%30.1%

The estoppel-confirmed figure is the only one either the lender or the broker could actually stand behind at closing -- exactly the kind of documentation gap that matters more as rental vacancy rate data shows tenant turnover slowing and leases ageing without being formally updated.

№ 04

The solution

A mortgage agent licensed under Ontario's Mortgage Brokerages, Lenders and Administrators Act treated the seller's own lease copies as a starting point, not proof of what any tenant was actually paying.

First, required a signed estoppel certificate from every tenant in the building -- commercial and residential alike -- confirming rent, term and deposit directly from the tenant, not the landlord. The two residential tenants confirmed exactly what their leases already showed. The commercial tenant did not.

Second, requalified the file on the estoppel-confirmed $1,750/month commercial rent, rather than the seller's own $2,200 figure, once the gap surfaced.

Third, documented the rent reduction's own history in writing, so the file's own notes -- not just the closing figures -- reflected what had actually happened to the lease over the years.

Signed estoppel certificate from each residential tenant, confirming rent, term and deposit
Signed estoppel certificate from the ground-floor commercial tenant, confirming its own rent, term and deposit
Written explanation of the gap between the seller's lease copy and the estoppel-confirmed rent
Standard investment-purchase documentation for income, down payment and credit
Updated rent roll reflecting the estoppel-confirmed figures, not the original lease copies
№ 05

The outcome

The purchase funded conventionally at 30.1% total debt service on the estoppel-confirmed rent roll -- a full 0.6 percentage points above what the seller's own stale lease copy alone would have shown.

Because this is an uninsured, non-owner-occupied purchase, CMHC's ratio maximums do not apply directly; the 29.5% and 30.1% figures are informational, showing exactly what the estoppel process itself changed.

№ 06

What to take from this file

  • 01A seller's own lease copy is not proof of what a tenant is actually paying today. Rent can be renegotiated informally over the years without the paperwork ever catching up.
  • 02An estoppel certificate, signed by the tenant directly, is the reliable way to confirm rent, term and deposit -- not a copy of a lease the landlord happens to have on file.
  • 03Get one from every tenant, not just the ones that seem uncertain. The two residential leases matched perfectly; only the commercial one didn't, and there was no way to know which would be wrong in advance.
  • 04A stale rent figure can understate total debt service just as easily as it can overstate it. Either direction is a problem if the file closes on a number the actual tenant won't confirm.

Sources

Every regulatory figure in this file traces to one of these primary sources. Client details and anything that varies by lender are illustrative, as flagged below.

Illustrative in this file — lender-specific, not rules:

  • 5.35% contract rate — rates move daily; not a quote.
  • 30% down payment — each mixed-use-comfortable lender sets its own down-payment convention for a commercial-component investment purchase; not a published rule.
  • the 50% rental-income add-back — each lender publishes its own add-back or offset treatment; there is no universal rule.

Authority & provenance

How this case file was built

We publish the origin, the verification method and the reviewer for every case file, so you can judge how far to trust it before you rely on it with a client.

Where it comes from

Derived from files handled by Treadstone’s fulfillment desk and from scenarios contributed by partner brokerages. Names, employers, exact amounts and dates are changed so no client or file is identifiable.

Provenance: Composite — a pattern seen repeatedly on fulfilled files, not a single transaction.

What is verified

Every regulatory figure traces to a primary source listed above and was checked against it on the date shown. The arithmetic is recomputed by machine on every rebuild.

Anything that varies by lender is labelled illustrative rather than stated as a rule.

Who reviewed it

Reviewed for Canadian regulatory accuracy before publication, and re-checked whenever a cited rule changes.

Reviewed by: Nicholas Parson, Treadstone Associates — reviews every case file before publication.

First published 9 August 2026Rules last verified 9 August 2026Next scheduled review 9 February 2027

This case file is professional reference material for licensed mortgage professionals. It is not advice to a borrower, and it is not a lender commitment. Insurer rules, qualifying rates and provincial taxes change — confirm the current position with the insurer, regulator or lender before you rely on any figure here in a live file.

Treadstone fulfillment

Files like this are daily work for our desk.

Document collection, ratio math under multiple treatments, lender placement notes, and submission-ready packaging — for Canadian mortgage brokers who would rather be in front of clients.