RFI vs RFP vs ITT: Which Do You Need?
In plain English: an RFI (request for information) is a document that asks the market who can credibly do a piece of work. An RFP (request for proposal) is a document that asks shortlisted suppliers how they would do it and at what cost. An ITT (invitation to tender) is a formal request for suppliers to price a requirement the buyer has already defined.
RFI, RFP and ITT are used almost interchangeably in boardrooms and procurement teams, and that is where expensive mistakes begin. The difference between an RFI and an RFP is not a matter of paperwork. Each instrument answers a different question, and issuing the wrong one produces confident answers to the wrong question. This guide sets out what each one is for, where the RFQ fits, and a simple test for choosing the right route before a single supplier is contacted.
It is written for the people who have to defend the decision afterwards: the CFO, the CEO, the PE operating partner and the procurement lead who will be asked, twelve months on, why this supplier and why at this price.
RFI vs RFP vs ITT at a glance
| Instrument | The question it answers | Use it when | Does it select a supplier? | The common mistake |
|---|---|---|---|---|
| RFI (Request for Information) | Who in the market can credibly do this? | The market is unfamiliar, or nobody has tested it in years | No. It qualifies and shortlists | Scoring it as though it picks a winner |
| RFP (Request for Proposal) | How would you solve this, and at what cost? | The solution is not yet fixed and you want the market's thinking | Yes, after structured evaluation | Using it for a commodity that should turn on price |
| ITT (Invitation to Tender) | What will you charge to deliver this exact specification? | The requirement is fully defined, or the buyer is in the public sector | Yes, against published criteria | Issuing it before the requirement is understood |
| RFQ (Request for Quotation) | What is your price for this item or service? | A like-for-like commodity with a fixed specification | Usually, on price | Using it where service quality really matters |
What is an RFI?
An RFI, or request for information, is a qualification exercise. It asks the market a simple question: who can credibly do this work, and should we take them seriously? A well-designed RFI gathers evidence on capability, financial standing, security posture, references, appetite for the work and indicative pricing.
Its job is to turn a longlist into a shortlist and to sharpen the requirement. Suppliers' responses often reveal options, delivery models or cost drivers the buyer had not considered, which makes the later RFP or ITT better written.
What an RFI does not do is select a supplier. The responses are unpriced or only indicatively priced, unverified and written to impress. Scoring an RFI as if it were an evaluation simply rewards the supplier with the best marketing team. Use light pass or fail gates and a simple qualification score to decide who goes forward, and nothing more.
What is an RFP?
An RFP, or request for proposal, is a competitive evaluation. It sets out the business problem and the requirements, then asks shortlisted suppliers to propose how they would meet them and at what cost.
The defining feature of an RFP is that it invites the supplier to propose an approach. That makes it the right instrument when the solution is not yet fixed: a new managed service model, an ERP or finance system, a data platform, or a systems integration partner. You want the market's thinking as well as its pricing, and you want to compare different answers to the same problem.
Because responses differ in shape, an RFP only works if the evaluation is disciplined. The scoring model and its weightings should be agreed by the evaluation panel before any supplier sees the document. Every score should carry a written rationale. Where panel members disagree materially, the difference should be moderated rather than averaged away, because the disagreement is usually where the real risk sits.
What is an ITT (invitation to tender)?
An ITT, or invitation to tender, is a formal, specification-led competition. The buyer has already defined what it wants, and suppliers price against that definition. It is the standard route in UK public sector and regulated procurement, and it is increasingly used by private organisations that want the cleanest possible commercial comparison.
The strength of an ITT is precision. Every bidder prices the same scope, so the comparison is like for like and there is little room for a supplier to reshape the requirement in its own favour. Its weakness is the mirror image: if the specification is wrong, every bidder prices the wrong thing with great accuracy.
The difference between an RFP and an ITT, then, is how much of the answer the buyer already holds. An RFP asks the market how. An ITT tells the market what, and asks how much.
Public bodies run their tenders under the Procurement Act 2023 regime or through an established framework, and the procedure chosen, such as the open procedure or the competitive flexible procedure, shapes the timetable and what can be negotiated. That choice should be confirmed with the organisation's procurement or legal lead before the process is designed.
Where an RFQ fits
An RFQ, or request for quotation, is the simplest of the four. It asks for a price on a defined item or service where quality is broadly equivalent across suppliers: hardware, licences of a known product, or a standard commodity service. If the decision genuinely turns on price and delivery terms, an RFQ is the efficient choice. If service quality, delivery capability or long-term fit matter, it is the wrong one.
Why choosing the wrong instrument is expensive
The cost of the wrong choice rarely shows up during the process. It shows up in the contract.
- An ITT issued too early produces precise pricing for a requirement nobody fully understood. The variations, change requests and re-scoping arrive after signature, when the buyer has the least leverage.
- An RFP issued for a commodity service invites half a dozen suppliers to write essays about a decision that should have turned on price and service levels. The evaluation takes months, and the outcome is no better.
- An RFI scored as a selection picks the most persuasive brochure rather than the most capable supplier, and the organisation ends up negotiating with a preferred bidder it never properly tested.
- A process shaped by the incumbent, whichever instrument is used, produces requirements that describe the incumbent's service. The market test looks competitive and is not.
A four-question test for choosing
Before any document is drafted, answer four questions in order.
- Do we know who in the market can credibly do this? If not, start with an RFI to qualify the field and shape the requirement.
- Is the solution already fixed? If not, run an RFP so suppliers can propose different approaches and be evaluated against the same weighted model.
- Is the requirement fully specified, or are we bound by public procurement rules? If so, an ITT will give the cleanest and most defensible commercial comparison.
- Is the real issue price on a contract we are otherwise content with? Then a full competitive process may not be needed at all.
Many material selections use more than one instrument in sequence: an RFI to qualify the market, followed by an RFP or ITT for the shortlist. What matters is that each stage is used for the question it is designed to answer.
The fourth option: do not go to market
Sometimes the honest answer is that no formal process is needed. If the incumbent is performing, the requirement has not changed and the issue is commercial, a well-prepared negotiation can achieve the outcome faster and at lower cost than a full competition.
Even then, evidence matters. A light market test gives the buyer credible benchmarks and real leverage at renewal, and it gives the board documented assurance that the decision to stay was tested rather than assumed. Staying with the incumbent is a legitimate result. Staying by default is not.
How FIVEPROOF™ uses all three
Intology runs RFI, RFP and ITT processes on the buyer's side of the table using FIVEPROOF™, our five-stage independent selection method. The RFI sits in the market analysis stage, where it qualifies a longlist built on fit rather than familiarity, with a recorded reason for every exclusion. The RFP or ITT follows for the shortlist, scored against a model the client's panel signed off before any supplier was contacted.
Choosing the right instrument is part of the first conversation, not an afterthought. We take no supplier commissions, we never bid for the delivery that follows, we work to a fixed fee, and the complete evaluation pack belongs to the client, so the decision can be audited without us in the room. Read more about our independent RFP and RFI consultancy, or see how the same discipline applies to finance system selection and independent ERP selection. For why independence matters in any selection, see are vendor-neutral advisors better for digital transformation.
Frequently asked questions
What is the difference between an RFI and an RFP?
An RFI gathers information to find out who in the market can credibly do the work and to shape the requirement. An RFP asks shortlisted suppliers to propose a solution and a price, which are then evaluated against an agreed scoring model. An RFI qualifies; an RFP selects.
Do you always need an RFI before an RFP?
No. If the market is well understood and the credible suppliers are already known, a formal RFI adds time without adding much value. It earns its place when the market is unfamiliar, has not been tested in years, or when the requirement itself is still uncertain.
Is an ITT the same as an RFP?
Not quite. Both lead to a supplier selection, but an RFP invites suppliers to propose an approach, while an ITT asks them to price a requirement the buyer has already defined. ITTs are standard in UK public sector procurement and give the cleanest like-for-like comparison.
Should an RFI be scored?
Only lightly. Pass or fail gates and a simple qualification score are useful for deciding who goes forward to the RFP or ITT. Treating RFI responses as an evaluation rewards presentation over capability and should be avoided.
When should you renegotiate rather than go to market?
When the incumbent is performing, the requirement has not materially changed and the issue is mainly commercial. A light market test can still provide benchmarks and leverage, so the decision to stay is evidenced rather than assumed.
Going to market on something material and not sure which route is right? That is part of our first conversation, and it is free. Arrange a confidential call.