Independent expert determination
An independent determination of the rent to be paid on review. Independent expert determination differs from arbitration in that the independent expert is not confined to the evidence presented by the parties.

Indexation
The regular adjustment of a rent in accordance with a specified index, eg the Retail Price Index.

Institutional lease
The typical institutional lease has been developed in England since the 1960s to meet the requirements of the pension funds and insurance companies investing in property. Generally tenants pay for all repairs and insurance to give the landlord a clear net income and minimise his management costs. Traditionally the term has been 25 years without options to break (see break clause) and with 5 yearly upwards only rent reviews.

Interim rent
A landlord may apply to the court to fix an interim rent when he has given notice of termination of a tenancy or where the tenant has served notice of a request for a new tenancy on the landlord.