You spot a public sector contract that looks perfect for your business. Then you notice the procurement jargon: PQQ, SQ, ITT, open procedure, restricted procedure. It can feel like a foreign language. This guide breaks it all down so you know exactly what stage you are at and what is expected of you.

What Is a PQQ or Selection Questionnaire?

A Pre-Qualification Questionnaire (PQQ) is a screening stage. Buyers use it to check whether suppliers meet a minimum standard before inviting them to bid. Since 2016, central government buyers in the UK have largely replaced the old PQQ label with the term Selection Questionnaire (SQ). Many local councils and NHS trusts use SQ too, though some still say PQQ. For practical purposes they mean the same thing.

The SQ asks about your organisation, not your solution. Typical questions cover:

  • Your legal status and company registration details
  • Financial health (turnover, accounts, insurance levels)
  • Technical and professional ability (similar past contracts, accreditations, case studies)
  • Any grounds for exclusion such as tax compliance or convictions

Buyers score the SQ and only invite the highest-scoring suppliers through to the next stage. This keeps the number of full bids manageable for both sides.

What Is an ITT?

An Invitation to Tender (ITT) is the full bid stage. Once you pass the selection stage, the buyer sends you the detailed specification and asks you to submit a complete proposal. This is where you describe exactly how you will deliver the contract, at what price, and to what quality.

ITT questions are much more specific. You might be asked to:

  • Write a method statement explaining your delivery approach
  • Provide a worked example or case study from a similar contract
  • Describe your quality management and safeguarding processes
  • Offer a social value commitment (see our post on how social value scoring works)
  • Submit a price schedule or break down your costs

ITT responses take considerably more time to write than an SQ. Budget accordingly.

Open Procedure vs Restricted Procedure

Understanding the two main procurement routes helps you know whether you will face one stage or two.

Open Procedure

There is no separate selection stage. Any supplier can download the full tender documents and submit a complete bid. The buyer evaluates all submissions together. Open procedures are common for lower-value or straightforward contracts. They save time for suppliers but can mean the buyer receives dozens of full bids to assess.

Restricted Procedure

This is the classic two-stage approach. Stage one is the SQ (or PQQ). The buyer shortlists a set number of suppliers — often three to five — and only those suppliers receive the ITT. If you do not pass the SQ, you go no further. Restricted procedures are typical for higher-value, more complex contracts.

The Procurement Act 2023 introduced a new Competitive Flexible Procedure that gives buyers more freedom to design their own process. Always read the procurement documents carefully to understand the exact stages for the contract you are pursuing.

Tips for the Selection Questionnaire Stage

Many SMEs lose at the SQ stage simply by rushing it or underselling themselves. Here is how to get it right.

  • Answer every question. A blank answer is an automatic fail for most buyers.
  • Check the minimum thresholds. If a buyer requires a minimum annual turnover, check that figure against your accounts before investing time.
  • Tailor your case studies. Match them to the sector and scale of the contract in question.
  • Keep your evidence up to date. Expired insurance certificates or old accounts can cause rejection.
  • Be honest about exclusion grounds. Buyers check. Hiding issues is far worse than disclosing and explaining them.

Tips for the ITT Stage

The ITT is where the contract is won or lost. The selection stage only gets you in the room.

  • Read the specification twice. Understand what the buyer actually needs before you start writing.
  • Use the marking scheme. Most buyers publish how many marks each section is worth. Spend your effort proportionally.
  • Answer the question asked. Do not paste in generic company text; show you understand this contract.
  • Use concrete examples and numbers. Vague claims score poorly. Specific outcomes from past contracts score highly.
  • Proofread carefully. Errors damage confidence in your professionalism.

A Quick-Reference Comparison

If you want a simple side-by-side view, here it is:

  • SQ / PQQ: About your organisation. Pass/fail or scored to shortlist. No price at this stage.
  • ITT: About your solution and price. Full evaluation. This decides who wins.
  • Open procedure: One stage only — SQ and ITT combined into a single submission.
  • Restricted procedure: Two separate stages. You must pass stage one to reach stage two.

Getting Started

If you are new to public sector bidding, it pays to find the right opportunities before worrying about which stage you are entering. Our guide on winning your first government contract covers how to assess whether a contract is a good fit for your business before you commit the time to apply. Always read the buyer's procurement documents in full — they will spell out exactly which procedure is being used and what each stage requires.

  • Identify whether the contract uses an open or restricted procedure
  • Check the SQ minimum thresholds before starting
  • Gather your financial documents and case studies in advance
  • Reserve serious writing time for the ITT stage
  • Use the published marking scheme to prioritise your effort