Interim order: Temporary court order of very limited duration, usually until the court has heard the full facts of a case.

Interlineation: Addition to a document after it has been signed. Such additions are disregarded unless they are initialled by the signatories and, if necessary, witnessed.

Interlocutory injunction: An injunction which lasts only until the end of the trial during which the order was sought, when it may be replaced by a permanent injunction.

Intestate: Person who dies without making a valid will.

Invitation to treat: An offer to receive an offer. Goods advertised by a shopkeeper are open to offers from customers. If goods are mistakenly marked with the wrong price, the retailer is not bound to accept that price because he has not offered the goods at that price: he has invited members of the public to make him an offer which he is entitled to accept or reject. A retailer who deliberately or consistently misprices goods, however, may be commiting an offence under the Consumer Information Act.

IOU: A written confirmation of a debt, signed by the debtor, which implies an undertaking to pay the sum owed at some future date. An IOU is not a negotiable instrument and may not be passed on to a third party.