The Lessee's Failure to Comply

Practical application:

This Court of Cassation decision confirms that the breach is instantaneous and non-repeating, so you are not obliged to serve a formal notice (mise en demeure) before taking legal action. Gather evidence of the sublease (contract, photos, witness statements) and instruct a lawyer to initiate proceedings for lease termination without delay. The tenant cannot remedy this by later asking you to join the sublease; the breach occurred at the moment of signing without your participation.

Practical application:

Under the case law, your failure constitutes an immediate breach, and your landlord can demand lease termination without issuing a formal notice. To minimise risk, immediately invite your landlord to ratify the sublease deed in writing, acknowledging their participation retroactively. If they refuse, consider offering a rent increase or other concession to preserve the main lease. Do not ignore the situation, as court action could force you to vacate the premises and pay damages.

Practical application:

Before completing the purchase, request a copy of the sublease contract and verify that the original landlord was called to participate in its execution, as required. If they were not, the head lease is exposed to immediate termination by the landlord under this case law, jeopardising your rental income. Insist on a remedy from the seller—such as obtaining the landlord's ratification before sale or an indemnity clause in the sale agreement—to protect your investment from eviction risk.