Most new tenancies these days are Assured Shorthold Tenancies or AST’s. These are usually for a fixed term of either six or twelve months. The agreement will stipulate terms regarding rent due dates, term of the tenancy, where your security deposit will be held, notice periods, specific responsibilities etc.
As a tenant it is your responsibility to adhere to the terms and conditions of your tenancy agreement. It is vital that you read your AST document thoroughly before signing it making sure you flag anything you're unsure of.
There could be a case that rents can be increased upon contract renewal or at any time if your contract becomes a statutory periodic tenancy. A statutory periodic tenancy is where the fixed term expires and the contract then rolls over month by month.
All contracts will stipulate the need for periodic inspections, or, if you're moving out, a check out inspection may be required, but you must be given at least 24 hours’ notice of a visit. You also have the right to properly fulfil any notice periods stipulated in your contract.
If you are a tenant entering into a fixed-term contract this also entitles you to a fixed rent, meaning that landlords cannot increase the cost of rent unless you have signed a contract agreeing to this. Rents can be increased upon contract renewal, or at any time your contract becomes periodic (a 'rolling’ month to month basis).