Co-Signer and Guarantor Agreements in Ontario Rentals: What Landlords Need to Know

Many Ontario landlords have been here: a tenant applicant looks promising but has thin credit, a short employment history, or income that's borderline for the rent amount. Someone suggests getting a co-signer or guarantor.

It sounds like a reasonable safety net. In practice, most landlords who use guarantor agreements discover the hard way that the protection is more limited than they expected.

This guide explains what co-signers and guarantors can and cannot do for Ontario landlords, how to set up an agreement that actually holds up, and the most common mistakes that leave landlords without the protection they thought they had.

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Co-Signer vs. Guarantor: The Difference Matters

These terms are often used interchangeably, but they describe different legal arrangements with different consequences.

A co-signer signs the lease itself alongside the primary tenant. Legally, a co-signer who signs the lease is a co-tenant — they hold the same rights and obligations under the Residential Tenancies Act as any other tenant. They can occupy the unit, they must pay rent, and they have all the protections the RTA provides. If you want to evict a co-signer, you need to go through the same LTB process as you would for any tenant.

A guarantor signs a separate agreement — not the lease — promising to pay the tenant's rent or damages if the tenant doesn't. A guarantor is not a tenant. They have no right to occupy the unit and no RTA protections. But they also fall outside LTB jurisdiction entirely.

The distinction matters because most landlords who think they have a guarantor actually want the second option: someone who will cover the bill if the tenant doesn't pay, without gaining tenancy rights themselves. That arrangement is a guarantor agreement, not a co-signed lease.

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Can You Legally Require a Co-Signer or Guarantor in Ontario?

Yes — at the application stage.

When you are screening applicants and have not yet offered or signed a lease, you can set your own criteria. Requiring a co-signer or guarantor as a condition of offering a tenancy is not discrimination under the Ontario Human Rights Code, as long as you are applying that requirement consistently and not using it as a pretext to screen out applicants based on a protected characteristic (race, family status, source of income, etc.).

What you cannot do:

• Add a co-signer requirement to the Ontario Standard Lease after signing. The Standard Lease is a prescribed form under the RTA. You cannot add additional terms that take away rights the RTA gives tenants. A clause requiring a co-signer mid-tenancy, or adding guarantor conditions as an addendum that limits the tenant's rights, is unenforceable.
• Require a co-signer because an applicant receives social assistance. Source of income is a protected ground under the Ontario Human Rights Code. Requiring a co-signer specifically because a tenant receives ODSP or Ontario Works — when you would not require one from a salaried applicant with comparable income — is discriminatory.
• Treat the guarantor agreement as a substitute for proper screening. A guarantor covers one risk (non-payment). It does not help with property damage, illegal activity, or an LTB process that takes months regardless of who guaranteed the rent. See tenant screening red flags for a fuller picture.

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How a Guarantor Agreement Works in Ontario

A guarantor agreement is a contract between the landlord and a third party. It is governed by contract law — not the RTA. The LTB has no jurisdiction over it.

For a guarantor agreement to hold up, it needs to meet the basic requirements of a valid contract:

• Offer and acceptance. Both parties sign.
• Consideration. The guarantor receives something of value. In most cases, this is the landlord's agreement to rent to the tenant — the landlord would not otherwise offer the tenancy.
• Certainty of terms. The agreement must be specific about what is guaranteed: the rent amount, the term, the maximum liability, and the conditions under which the guarantee applies.

What to include in a guarantor agreement

A well-drafted guarantor agreement in Ontario should specify:

1. The parties. Full legal names and contact information for the landlord and the guarantor.
2. The tenancy. Property address, tenant name, monthly rent amount, and lease start date.
3. Scope of the guarantee. What exactly is the guarantor responsible for — unpaid rent only, or also damage claims? Up to what dollar amount?
4. Duration. Does the guarantee apply for the initial lease term only, or does it continue if the tenancy converts to month-to-month?
5. Notice requirement. How and when the landlord will notify the guarantor of a default before pursuing them.
6. Enforcement mechanism. Explicitly state that enforcement is through Small Claims Court, not the LTB.

Keep a signed copy in your records. If you ever need to use it, you will need to produce it in court.

For general lease documentation standards, see how to write a lease agreement in Ontario.

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The Critical Limitation: The LTB Cannot Enforce Guarantor Agreements

This is where most landlords discover the gap.

When a tenant stops paying rent, the standard route is to serve an N4 notice, file an L1 application, and proceed through the LTB. The LTB issues an order for rent arrears and, if necessary, eviction. See N4 notice Ontario and L1 application Ontario for that process.

But the LTB's jurisdiction is limited to landlords and tenants under the RTA. A guarantor is neither. The LTB cannot:

• Name a guarantor in an eviction order
• Order a guarantor to pay rent arrears
• Enforce a guarantor agreement in any way

To recover from a guarantor, you need to go to Ontario Small Claims Court, which handles claims up to $35,000. You file a separate civil action against the guarantor based on the contract you have with them.

This creates a practical reality: pursuing a guarantor in Small Claims Court takes time, costs money, and requires you to actually have a signed, enforceable guarantor agreement. If the agreement was informal, verbal, or poorly drafted — it may not hold up.

The LTB process against the tenant runs in parallel. In most cases, you pursue both simultaneously: the N4/L1 process against the tenant for eviction and the Small Claims action against the guarantor for the unpaid rent.

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London and Southwestern Ontario: Local Context

In London, the London Regional LTB office handles matters for Middlesex, Elgin, Oxford, and surrounding counties. L1 hearings for rent arrears typically take 8–14 weeks from application to hearing order, with Sheriff enforcement adding another 4–8 weeks after that.

For a London landlord with a $2,100/month 2BR unit, that timeline means $3,000–$5,000 in arrears can accumulate before eviction is complete. A guarantor agreement does not shorten that timeline — it gives you a parallel recovery path after the fact.

If you are using a guarantor to manage income risk on a tenant, make sure the guarantor has stable income and assets in Ontario. An out-of-province or foreign guarantor is extremely difficult to collect from through Small Claims.

If your unit was first occupied on or after November 15, 2018, it is also exempt from Ontario rent control — you can raise the rent to any amount on renewal without the provincial guideline cap. See Ontario rent control exempt properties for details. This affects the risk math if you are pricing a unit conservatively to retain a weaker tenant.

For St. Thomas and Strathroy landlords, the same LTB regional office applies. Timelines are comparable.

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When a Guarantor Agreement Makes Sense

A guarantor agreement makes sense in a limited set of circumstances:

• Young applicants with no credit history (students, first-time renters) who have an employed parent willing to guarantee.
• Self-employed applicants with irregular income but documented assets, where a co-applicant would complicate ownership questions.
• Short-term bridge situations where a tenant's income will increase and you want to rent to them now.

A guarantor agreement is not a substitute for a qualified applicant. The best outcomes come from thorough screening up front. A guarantor makes a weak application somewhat safer — it does not make it strong.

If you are consistently finding yourself considering guarantors, that is often a signal to revisit your application criteria, your rent pricing, or your listing quality. A well-priced, well-presented unit in London attracts qualified applicants. Tenant placement services that run professional screening eliminate most of these decisions.

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Common Mistakes

1. Assuming the guarantor can be named in the LTB application. They cannot. The LTB has no jurisdiction over a guarantor. If you serve an N4 and file an L1, the guarantor is not part of that proceeding.

2. Using an informal letter or email instead of a signed agreement. A written guarantor agreement signed by both parties before the tenancy begins is the minimum. A casual email from the guarantor saying "I'll cover the rent" is not an enforceable contract.

3. Not specifying the duration. If your lease is for one year and the tenancy converts to month-to-month, does the guarantee continue? If the agreement doesn't say, you may have no coverage after year one.

4. Not specifying the maximum liability. A guarantor who signs an open-ended guarantee can claim they didn't understand the full exposure. Cap it: "the guarantor is liable for up to $X in unpaid rent and documented damage."

5. Co-signing the lease when you wanted a guarantor. A co-signer becomes a co-tenant with full RTA rights. You cannot evict a co-tenant more easily than a primary tenant — you still need to go through the LTB. If your goal was to have a backup payer without adding a tenant, use a separate guarantor agreement.

6. Failing to keep a signed copy. If you need to file in Small Claims Court, you need the original signed agreement. Keep it with your tenancy documentation for the full duration of the tenancy plus two years. For general documentation standards, see landlord record-keeping Ontario.

7. Not verifying the guarantor's financial standing. Requiring proof of income, a credit check, or employment verification from the guarantor before signing is reasonable and advisable. A guarantor without the means to pay is not a safety net.

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Comparison Table: Co-Signer vs. Guarantor

	Co-Signer (signs lease)	Guarantor (separate agreement)
RTA applies?	Yes — they are a co-tenant	No — separate contract
LTB jurisdiction?	Yes	No
Occupancy rights?	Yes	No
Enforcement route	LTB + Sheriff	Small Claims Court
Eviction process required?	Yes (same as tenant)	No
Added to the Standard Lease?	As a co-tenant (signature)	As a separate document
Risk to landlord if it fails	Full LTB process	Separate civil litigation

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FAQ

Can I add a co-signer clause to the Ontario Standard Lease? The Standard Lease does not have a co-signer section. You can add a co-tenant's name on the signature lines — that makes them a co-tenant with full RTA rights. You can attach a separate guarantor agreement as an addendum, but it must not reduce the tenant's RTA rights. It exists beside the lease, not as part of it.

Does the last month's rent deposit still apply if I have a guarantor? Yes. The last month's rent deposit is a separate requirement under the RTA. A guarantor agreement does not change your obligation to apply the deposit correctly. See what can a landlord deduct from last month's rent in Ontario for how deductions work on vacating.

Can I require a guarantor for every applicant? You can apply the requirement consistently across all applicants. Applying it selectively to specific groups — particularly those with protected characteristics under the Human Rights Code — is discriminatory. Be consistent and document your criteria.

What if the guarantor refuses to pay? File in Ontario Small Claims Court. Bring the signed guarantor agreement, the signed lease, documentation of unpaid rent (payment ledger), and any LTB orders if applicable. The process is designed for self-represented parties. If the amount exceeds $35,000, you would need Divisional Court.

Is a guarantor agreement still valid if the tenant renews their lease? It depends on what the agreement says. A well-drafted agreement will specify whether the guarantee extends to renewals or converts to month-to-month tenancy. If it doesn't address renewals, you may need a new agreement for the renewal period.

What happens to the guarantor agreement if the tenancy is assigned or subletted? Assignment and subletting changes the tenancy relationship. A guarantor agreement typically names the original tenant. If the tenancy is legally assigned, the original guarantor's liability may end with the original tenant's. Revisit the agreement before approving any assignment.

Can a co-signer be evicted separately from the primary tenant? No. All tenants on the lease are subject to the same RTA process. You cannot selectively evict one co-tenant while keeping another. An eviction order applies to all occupants of the unit.

Does Ontario law limit what I can charge a guarantor? The guarantor agreement is a private contract, but it must be reasonable and not unconscionable. You cannot, for example, build in penalties or fees beyond actual rent arrears and documented damages. Courts will reduce awards to actual verified losses.

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Summary

Co-signer and guarantor agreements can provide a useful secondary layer of protection for Ontario landlords — but they operate outside the RTA, not inside it. The LTB cannot enforce a guarantor agreement. You recover from a guarantor through Small Claims Court, which is a separate process running parallel to any LTB proceedings.

A well-drafted guarantor agreement, signed before the tenancy begins and specific about scope, duration, and maximum liability, is enforceable. An informal arrangement is not.

Use guarantors selectively — for applicants who are genuinely close to qualifying — and maintain your screening standards rather than treating a guarantor as a substitute for a qualified tenant. The best protection is always a carefully screened tenant who doesn't default.

If reviewing and negotiating applicant situations sounds like more friction than you want, Prospera Properties handles screening, lease preparation, and placement for landlords across London, St. Thomas, and Strathroy. Learn more at /services/tenant-placement.