ITT (Invitation to Tender)

An Invitation to Tender is the formal document package issued to suppliers, containing the full specification, contract terms, evaluation criteria, and instructions for submitting a compliant bid. The term is most common in UK, Commonwealth, and EU procurement. Unlike an RFP, an ITT presupposes that the contracting authority has fully defined its requirement and is seeking competitive prices for a fixed scope.

In a restricted procedure, the ITT is sent only to pre-qualified suppliers (those who passed the selection questionnaire stage). In an open procedure, it is published publicly and any interested supplier may submit a tender. ITTs for complex contracts can run to hundreds of pages, covering technical specs, service levels, data handling requirements, and standard contract terms such as NEC4 or FIDIC for works.

For vendors, an ITT response — known as a tender — must be fully compliant with every mandatory requirement. Non-compliance on even minor administrative points (e.g., missing a signed declaration) can result in immediate disqualification. Preparation typically involves a bid manager, subject-matter experts, and a pricing team. Submission via e-procurement portals is now the norm; late electronic submissions are virtually never accepted regardless of technical cause.