Invitation to tender (ITT): A complete guide for suppliers and buyers

Imagine you’re a supplier with a high-quality service — maybe you build infrastructure, manage IT systems, or provide cleaning for large facilities. You know your team can deliver, but you keep missing out on big public contracts. 

One things is sure - your success starts with one thing: understanding the Invitation to Tender (ITT).

For suppliers, an ITT is often the gateway to large, stable contracts, especially in the public sector. 

But ITTs can be confusing. They’re formal, full of legal language, and involve strict rules. Many businesses either ignore them or make small mistakes that cost them the entire opportunity.

This guide simplifies everything. Whether you’re new to tendering or looking to improve your strategy, we’ll break down the entire ITT process — from definitions to best practices — in clear, practical terms.

Let’s start by answering the most basic but important question: what exactly is an ITT, and why should you care?

An Invitation to Tender (ITT) is a formal request sent by an organization — often in the public sector — asking suppliers to submit bids for delivering a specific product or service. It’s not a casual request. It’s a structured, legally binding process with clear rules, deadlines, and evaluation criteria.

In simple terms, an ITT is how governments and large companies say:

“Here’s exactly what we need. If you can deliver it, tell us how — and at what price.”

Why Buyers Use ITTs?

For buyers, especially in public institutions, ITTs are used to:

• Ensure transparency and fairness in vendor selection
• Comply with legal frameworks (e.g., EU procurement directives)
• Compare offers on an equal footing — same scope, same criteria
• Get the best value without risking corruption or favoritism

Why ITTs Matter for Suppliers?

If you’re a supplier, responding to ITTs gives you access to:

• Large, long-term contracts (often in the 5–7 figure range or more)
• Predictable revenue from reliable institutions
• A way to grow into new sectors or regions
• Competitive credibility (winning tenders builds your reputation)

A Simple Example of ITT

Let’s say a city council needs to install energy-efficient street lighting across 200 locations. They issue an ITT outlining:

• The scope of work
• Technical and legal requirements
• Evaluation criteria
• A strict timeline

You, as a supplier, can read this ITT and submit a detailed proposal. If your bid meets the requirements and offers the best value, you win the contract.

That’s the power of the ITT process — it opens doors for capable suppliers while protecting buyers from risky decisions.

Now that you understand what an ITT is and why it’s essential, let’s see how it compares to other common procurement methods like RFPs and RFQs.

In procurement, not all requests are created equal. You might see terms like ITT, RFP, and RFQ used almost interchangeably — but they serve very different purposes.

Understanding the difference can help buyers choose the right tool for their needs and help suppliers avoid wasting time on bids they’re not suited for.

When to Use an ITT (vs an RFP or RFQ)?

Choose ITT when:

• You know exactly what you need
• The project is well-defined and structured
• You want bids that are directly comparable
• You’re legally required to follow a formal process (often in public sector)

Use an RFP when:

• You need help designing a solution
• You want to evaluate ideas, not just prices
• The problem is complex (e.g., building a custom IT platform)

Use an RFQ when:

• You just need prices for off-the-shelf items
• Speed matters more than structure
• You’re sourcing simple products or repeat purchases

Example of Using ITT, RFP, and RFQ

Let’s say you’re renovating your office building:

• An ITT is like hiring a construction firm with a detailed blueprint and asking them to bid on exactly that.
• An RFP is like saying, “I want to modernize the space — show me how you’d do it.”
• An RFQ is like asking for a price on 500 chairs based on a product catalog.

Knowing the difference saves time, reduces risk, and increases the chance of a good outcome — whether you’re buying or selling.

Next, let’s walk through the actual ITT process step by step, from both the buyer’s and supplier’s perspectives.

Understanding the ITT process is crucial. For buyers, it ensures transparency and better vendor selection. For suppliers, it’s the key to submitting a winning bid.

Let’s walk through the journey from both sides — and highlight where decisions really matter.

How to Run an Effective ITT as a Buyer

A well-managed ITT helps avoid disputes, delays, and budget overruns. Here’s how buyers typically structure the process:

1. Define your requirements
   
   • Clearly outline what you need: deliverables, timelines, budget range.
   • Involve internal stakeholders early (legal, technical, financial teams).
2. Draft the ITT document
   
   • Include all mandatory information:
   • Scope of work
   • Eligibility criteria
   • Evaluation methodology
   • Submission instructions and deadlines
3. Publish the ITT
   
   • Use platforms that reach the right suppliers (e.g., national portals, specialized tools like Tendify).
   • Set a fair deadline, typically 2–6 weeks depending on complexity.
4. Manage supplier questions
   
   • Allow a question period (clarification window).
   • Share answers with all bidders to maintain fairness.
5. Evaluate submissions
   
   • Use a scoring system aligned with your evaluation criteria.
   • Document decisions for transparency.
6. Award the contract and give feedback
   
   • Notify both successful and unsuccessful bidders.
   • Provide feedback to help suppliers improve.

How to Respond Professionally as an ITT Supplier?

Responding to an ITT can feel overwhelming, but with a clear process, it becomes manageable and repeatable.

1. Find relevant opportunities
   
   • Use tools like Tendify to filter ITTs by sector, region, or value.
   • Don’t chase everything — choose bids that fit your capabilities.
2. Study the ITT carefully
   
   • Highlight:
     
     • Mandatory requirements (e.g., certifications)
     • Evaluation weightings
     • Submission format
     • Ask questions during the clarification period if anything is unclear.
3. Prepare your response
   
   • Follow the required format exactly.
   • Cover:
     
     • Technical proposal (how you’ll deliver)
     • Financial proposal (clear pricing breakdown)
     • Legal and compliance docs (licenses, insurances, etc.)
4. Review and submit on time
   
   • Double-check for missing documents or errors.
   • Submit via the correct platform before the deadline — even 1 minute late may disqualify you.

Tip for Both Sides

The most successful ITTs are those where both parties follow a disciplined process. Buyers get better results. Suppliers save time and boost win rates.

Now that you understand the full process, let’s look at how to craft or respond to an ITT effectively, using best practices that increase success.

Now that you know how the process works, the next step is execution. Whether you’re a buyer writing the ITT or a supplier responding to one, the way you prepare your documents can be the difference between success and failure.

Let’s break it down from both perspectives — with practical advice you can act on immediately.

For Buyers: Writing a Clear and Effective ITT

When the ITT is clear, suppliers submit better bids. That means fewer delays, lower risk, and better value.

Here’s how to write a strong ITT:

• Be specific about the scope
  
  • Describe exactly what is required — deliverables, locations, timeframes.
  • Avoid vague phrases like “as needed” or “when possible.”
• Separate mandatory and optional criteria
  
  • Clearly list what’s required to qualify vs. what’s nice to have.
  • This avoids confusion and unnecessary disqualifications.
• Explain how you’ll evaluate
  
  • Define scoring breakdowns (e.g., 40% price, 30% technical, 30% quality).
  • Let bidders know what matters most — this improves the quality of responses.
• Make it easy to respond
  
  • Provide a response template if possible.
  • Use plain language — avoid overly legal or bureaucratic phrasing.

For Suppliers: Writing a Strong ITT Response

Responding to an ITT is not about selling. It’s about proving that you understand the requirement and can deliver exactly what’s needed.

Keep this checklist in mind:

• Follow instructions exactly - if the ITT says “submit as PDF by 12:00 CET,” do exactly that. No exceptions.
• Tailor your response - don’t copy-paste old proposals. Speak directly to the buyer’s problem.
• Address all criteria clearly - use headings that match the ITT sections. Make it easy to score your bid.
• Support your claims - add case studies, client references, or certifications that prove your experience.
• Be transparent with pricing - include a full breakdown. Hidden costs raise red flags and may disqualify you.
• Review everything - one missing document can eliminate your bid. Use a checklist to verify completeness.

A Common Mistake: Overcomplication

Whether you’re writing or responding, remember this: simple is powerful. Clear, direct communication builds trust — and makes decision-making easier on both sides.

Next, let’s look at how Tendify can help you.

With Tendify, suppliers can stop wasting time and start focusing on tenders they can actually win.

Here’s how we help:

• Smart matching - automatically discover tenders that match your industry, location, and capabilities — across multiple platforms.
• Collaboration tools - work seamlessly with your team to prepare bids, assign tasks, and track deadlines in one shared workspace.
• Document management - store and reuse standard documents (certificates, case studies, financial forms) so you never start from scratch.
• Deadline reminders & alerts - get notified early, so you’re never caught off guard by last-minute submissions.

In today’s procurement landscape, efficiency is competitive advantage.