Your rights depend on where you live, your tenancy type and what your tenancy agreement says. In England, rent usually cannot be increased during a fixed term unless the agreement allows it, while a periodic tenancy requires the landlord to follow the correct legal notice procedure and frequency limits. You may be able to challenge an increase that is above the market rent, but the relevant deadline matters. Check the latest guidance on GOV.UK or contact a housing adviser, as Wales, Scotland and Northern Ireland have different rules.