A rent increase should strengthen a portfolio, not create an avoidable dispute, void or compliance failure. The right question is not, "What percentage can I add?" It is, "What is a well-evidenced market rent, and have we used the right process for this particular tenancy?" There is no single UK-wide percentage cap on private rent increases. Housing law is devolved and the legal position differs in England, Wales, Scotland and Northern Ireland. For professional landlords, age