Published 17 February 2026 by eSourcingData
The invitation to tender is where you tell the market what you need, how to respond and how you will decide. A clear ITT attracts capable suppliers and produces bids you can actually compare. A vague one generates clarification questions, weak responses and challenge risk. This guide covers how to write one well.
The specification is the heart of the ITT. Wherever you can, describe the outcomes you need rather than dictating a fixed method, because outcome based specifications let suppliers propose better ways of delivering and stop you accidentally excluding good solutions. Prescribe method only where safety, interoperability or a genuine constraint demands it.
Be specific about scope, volumes, service levels and anything that materially affects price. Suppliers price risk, so every ambiguity gets loaded with contingency or turned into a clarification question. Precision here is what gives you comparable, competitive bids.
Separate mandatory requirements from desirable ones and say which is which. Bidders need to know what is a pass or fail threshold and what is a scored preference, so they can pitch their response at the right level.
State the conditions of participation clearly, covering legal standing, financial standing and technical capability. Under the Procurement Act these must be proportionate to the contract, so ask only for what genuinely tests a supplier can deliver, and avoid thresholds that quietly favour large incumbents.
Explain exactly what evidence suppliers must provide against each condition and in what format. Clear evidence requirements reduce the volume of incomplete submissions and make your compliance checks quick and consistent.
Give a short reason in your own records for each condition you impose. If a supplier queries a requirement, a contemporaneous rationale is far more convincing than an explanation invented after the fact.
Set out your award criteria, sub criteria and their weightings in the ITT, and describe how each will be scored. Suppliers who understand exactly how they will be judged write sharper, more relevant answers, which makes evaluation easier and the eventual award more defensible.
Reflect what genuinely matters in the weightings. If quality carries most of the value, weight it accordingly rather than letting price dominate by default. Under the most advantageous tender approach you are free to balance quality, price and social value as the contract requires.
Include scoring descriptors so bidders and evaluators share the same understanding of what a strong answer looks like. Descriptors published in the ITT double as your evaluation standard, keeping the two perfectly aligned.
Ask questions that map directly to your criteria, and only the questions you will actually score. Every extra question adds effort for suppliers and reading time for evaluators, so cut anything that does not inform the decision. Quality of questions beats quantity every time.
Set word or page limits and say whether material beyond the limit will be read. Limits force suppliers to prioritise and make responses comparable, while an unbounded question invites padding that helps nobody.
Tell suppliers what evidence or examples you expect within each answer. A question that asks for a demonstrable, evidenced response produces a far more useful bid than one that invites generic assertions.
Provide the timetable, the clarification process and deadline, submission format and any templates. Clear logistics prevent the avoidable disqualifications and last minute confusion that undermine an otherwise good process. Suppliers should never lose out on a technicality you failed to explain.
Include the draft contract and its key terms in the ITT, not after award. Suppliers price against the terms they will be held to, so surfacing the contract early gives you accurate pricing and avoids painful renegotiation once you have chosen a winner.
Proofread the whole pack for internal consistency. Contradictions between the notice, specification and contract are a frequent source of clarifications and, at worst, grounds for challenge.
Build consistent ITTs your whole team can reuse
eSourcingData structures your ITT, questions and evaluation criteria in one place, keeping documents aligned and every clarification and version fully audited.
See eSourcingDataWhat is an invitation to tender?
An invitation to tender, or ITT, is the document set that tells suppliers what you need, the conditions they must meet, how to respond and how their bids will be evaluated and awarded.
Should I specify outcomes or methods?
Favour outcome based specifications so suppliers can propose the best way to deliver. Prescribe a method only where safety, interoperability or a genuine constraint requires it.
Do I have to publish award criteria in the ITT?
Yes. Award criteria, sub criteria and weightings must be set out in advance and applied as stated, so suppliers know exactly how their bids will be judged.
Should I include the contract in the ITT?
Yes. Providing the draft contract and key terms up front means suppliers price against the terms they will actually be held to, giving you accurate bids and avoiding later renegotiation.
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