Ontario Landlords: A Complete Guide to the A1 Application for Sublet and Assignment Issues (2025 Update)

The A1 Application – Application About a Sublet or Assignment is used when disputes arise between landlords and tenants regarding the subletting or assignment of a rental unit under the Residential Tenancies Act, 2006 (RTA).

This form allows either the landlord or the tenant to request an order from the Landlord and Tenant Board (LTB) when disagreements occur about:

• Subletting a rental unit
• Assigning a tenancy to another person
• Rejection of an assignee or sublet applicant
• Landlord's unreasonable refusal
• Tenant's improper sublet or unauthorized assignment

This application protects both sides by ensuring that all sublet and assignment arrangements comply with Ontario law.

When an A1 Application Can Be Filed

Either a tenant or landlord may file an A1.

A tenant may file if:

• The landlord unreasonably refuses to allow an assignment
• The landlord refuses to respond to a written request to assign
• The landlord charges an illegal fee
• The landlord fails to follow the rules under the RTA regarding assignments or sublets

A landlord may file if:

• The tenant sublets without permission
• The tenant assigns the tenancy to someone else without consent
• The tenant collects rent above the lawful rent during an unlawful sublet
• The tenant attempts to profit from the unit (e.g., charging Airbnb-style rates)

The A1 form allows the LTB to make a binding decision on the dispute.

Understanding Sublets vs Assignments

Many disputes arise because tenants or landlords misunderstand the difference.

What the A1 Application Can Resolve

The A1 application allows the LTB to order:

• Whether a landlord's refusal to allow assignment was reasonable
• Whether a tenant sublet or assigned the unit illegally
• Whether a landlord must consent to an assignment
• Whether rent collected by a tenant during an improper sublet must be reimbursed
• Whether the tenancy should be terminated due to unauthorized assignment
• Whether compensation is owed

This application is often used to address unauthorized occupancy situations.

Evidence Required for an A1 Application

The Board expects clear documentation, such as:

• Copies of emails or letters requesting assignment/sublet
• Proof of landlord consent or refusal
• Screenshots of advertisements (if unauthorized sublet occurred)
• Bank records showing rent overcharges
• Lease agreements
• Communications with prospective subtenants or assignees
• Social media or short-term rental listings
• Statements from affected parties

The stronger and clearer the evidence, the better.

Filing the A1 Application

The A1 can be filed:

• Online through the LTB e-File portal
• By mail or courier
• In person (limited locations)

The applicant must include:

• Completed A1 form
• Supporting evidence
• Filing fee (if applicable)
• Contact information for all parties involved

The LTB will issue a Notice of Hearing.

Serving the Other Party

The applicant must serve the opposing party with:

• A copy of the A1 application
• Notice of Hearing
• All evidence being used

Service must comply with RTA section 191 and the LTB Rules of Procedure.

What Happens at the A1 Hearing

At the hearing, the LTB Member will consider:

• Whether the landlord acted reasonably
• Whether the tenant followed the correct procedure
• Whether an unauthorized occupant is living in the unit
• Whether additional rent was unlawfully collected
• Whether the tenancy should be transferred, terminated, or modified
• Whether compensation is appropriate

The LTB may issue orders requiring:

• Approval of assignment
• Reimbursement of overcharged rent
• Eviction due to illegal sublet
• Permission for the tenant to assign the tenancy
• Termination of tenancy (in severe cases)

Common Mistakes That Lead to A1 Problems

Common issues include:

• Tenants subletting on Airbnb without consent
• Landlords refusing an assignment without explanation
• Missing written requests or proof
• Landlords charging illegal "administration fees"
• Tenants collecting inflated rent from subtenants
• Landlords failing to respond to assignment requests

The A1 resolves these disputes by allowing the LTB to make a final decision.

When to Seek Professional Help

An A1 case often involves:

• Complex documentation
• Disputes about communication
• Unauthorized occupants
• Claims of unreasonable refusal
• Monetary compensation requests

Professional assistance ensures the application is properly completed, evidence is organized, and the applicant is prepared for the hearing.

Sources

1. Residential Tenancies Act, 2006 — Sections 95–104
2. Landlord and Tenant Board — A1 Form
3. LTB Interpretation Guidelines
4. LTB Rules of Procedure