According to the CLCV association's barometer, more than one out of every three rental listings in Paris and Seine-Saint-Denis exceeds the rent ceiling set by local regulations. This situation poses a risk for landlords, who could be required to lower the rent, reimburse the tenant, and face fines of up to 15,000 €. Approximately 70 municipalities across France are affected by rent control measures. In Seine-Saint-Denis, 44 percent of rental listings exceed the allowed ceiling, with an average excess of about 155 € per month. Smaller properties, defined as those with an area of 14 square meters or less, are most affected, with 86 percent of non-compliant listings falling into this category. Landlords who exceed the limit could face fines of up to 5,000 €, with higher penalties of 15,000 € for companies. If a landlord exceeds the rent ceiling, tenants have several options. They can first write to the landlord requesting regularization of the lease. If no response is received, tenants can submit a complaint to the departmental conciliation commission, which offers a free and voluntary process to resolve disputes. If this fails, the tenant may take the matter to the judge for protection disputes, who can order the reduction of rent and reimbursement of any overpaid amounts. In cities like Paris, Lille, Lyon, Bordeaux, and Montpellier, the maximum allowable rent is determined annually by a prefectural decree, which sets a "reference rent increased." This measure was introduced experimentally by the Elan Law of 2018 and is currently in effect in about 70 municipalities. The CLCV analyzed 1,800 rental listings in Seine-Saint-Denis and Paris for its barometer published in late June 2026, uncovering significant discrepancies. On average, non-compliant rents exceed the legal ceiling by about 155 € per month, meaning tenants pay an additional 1,860 € annually. Fines for landlords can reach up to 15,000 €, but in practice, such penalties are rare. As of September 11, 2026, the City of Paris had issued only 17 fines, compared to about 747 cases resolved amicably. Meanwhile, tenants who reported excess rent recovered an average of 3,476 € during the regularization process. If a tenant reports an excess, the local prefect can issue a notice to the landlord, giving them two months to adjust the lease and reimburse the tenant for any overpayment. Failure to comply could result in fines of up to 5,000 € for individuals and 15,000 € for companies. However, in practice, fines are uncommon, and many disputes are resolved through negotiation. If a tenant wants to challenge a rent supplement, they must act quickly. They have three months after signing the lease to submit a complaint to the departmental conciliation commission. If this fails, they have three months from receiving a notice to take the matter to court, where the landlord must prove the supplement is justified. One key uncertainty remains: without a new law, rent control measures will expire by the end of November 2026. A proposed bill by socialist deputy Iñaki Echaniz aims to extend the measure for two years in the affected municipalities. The bill is set to be examined by the Senate starting October 21, which could determine the future of rent control in these areas.