If your contract is a short-term rental agreement and you want to stay, you do not have to renew the rental agreement. As soon as the fixed period expires, the lease becomes a «periodic lease», which means that it will continue under the same conditions as those that elapse from one month to the next. For companies that want to establish a universal lease, there is a trade-off between the width to cover all aspects of a lease and the specificity that there are no loopholes that accidentally allow misconduct. The contract must be understandable and reasonable for all parties. To start your rental on a solid legal basis, you need an up-to-date contract signed by all parties: renter, tenant and guarantor. Most leases in the UK are Tenancies (AST). .