The practical answer for England: for a private-rented-sector assured periodic tenancy, a landlord must serve a completed Form 4A at least two months before the proposed new rent starts. That is only the starting point. The first increase cannot begin until 52 weeks after the tenancy began; later increases are generally subject to a 52-week rule, and the new rent must start at the beginning of a tenancy period. A rent review should protect income and protect the relationship.

A rent increase should never arrive as a vague demand or a difficult conversation without context. For tenants, the immediate concern is affordability. For landlords and portfolio owners, the issue is equally important: a rent review that is poorly evidenced or incorrectly served can create avoidable disputes, delay income and damage a good tenancy. The short answer is that, for the relevant assured periodic tenancies in England, there is no general percentage cap such as 5%,