Section 13 Notice: The New Rules for Rent Increases. The Renters' Rights Act 2025 introduces significant new controls over how and when landlords can increase rent, centralising the process around the existing Section 13 notice (Housing Act 1988). With the abolition of fixed-term tenancies, Section 13 is set to become the only statutory mechanism for raising rent, making it a critical aspect of every landlord’s management strategy.