How to Write a Winning Public Sector Bid: A Practical Guide for Design Agencies

Finding the tender is only half the battle. The other half is writing a response that actually wins. Most design agencies that lose public sector bids don't lose because their work is bad — they lose because their bids are written like they're explaining the work to a peer, not to a panel evaluating dozens of responses against a fixed set of criteria.

This is a guide for changing that.

Understand what you're being evaluated against before you write a word

Every public sector procurement under the Procurement Act 2023 must award contracts based on the Most Advantageous Tender (MAT) — replacing the old MEAT (Most Economically Advantageous Tender) framework that was in place until February 2025. For a deep-dive into how evaluation scores are calculated and what the scoring rubric looks like in practice, see our guide to public sector evaluation criteria.

The shift matters. Under MAT, price is no longer required to be the dominant factor. Buyers have more flexibility to weight quality, social value, and approach heavily — sometimes to the point where the highest-priced bid wins if everything else is stronger. A typical weighting for a design or digital services contract might look like this:

• Quality / technical response: 60–70%
• Social value: 10–20%
• Price / commercial: 20–30%

Every ITT (Invitation to Tender) must publish its award criteria and their relative weightings. Read this section of the procurement documents before you do anything else. Your response needs to be structured around how marks are allocated, not how you would naturally tell the story of the work.

The difference between selection criteria and award criteria

These are two separate gates, and many agencies conflate them.

Selection criteria (also called pre-qualification or Stage 1 criteria) are about whether you're eligible to bid at all. They cover things like financial standing, insurance requirements, relevant experience, and whether you've done similar-scale work before. If a buyer is running a multi-stage process, you'll complete a Selection Questionnaire (SQ) before you see the ITT.

Award criteria are what you're actually marked on in the bid itself. These are specific to this contract — your approach, your team, your methodology, your social value commitments. This is where you win or lose.

Don't spend 80% of your effort proving you're qualified. That's the minimum bar. Spend 80% of your effort on the award criteria responses.

Writing for evaluators, not for peers

Public sector bids are assessed by a panel — typically 2–5 people, sometimes including technical specialists, commercial officers, and end users. They're scoring to a marking scheme against each question. They are not reading your response as a narrative. They're scanning it for evidence.

A few things that follow from this:

Structure every response around the question asked. If the question asks you to describe your approach to user research and how you'd involve citizens, every paragraph should be traceable to that question. Don't use a standard methodology section and hope it covers it.

Signpost explicitly. Panels appreciate when you make their job easier. "We will address accessibility in three ways: first… second… third…" is more useful than a beautifully written paragraph that buries the same information.

Use the buyer's own language. If their ITT refers to "co-design" or "service transformation" or "digital accessibility standards", use those exact terms in your response. It signals alignment and makes it easier for evaluators to score you against their framework.

Evidence every claim. Every claim you make needs supporting evidence. Not "we have extensive experience in user research" but "across eight public sector UX projects in the past three years, we've conducted over 140 user research sessions, including with users who have accessibility needs". Numbers, specifics, outcomes.

How to demonstrate experience without a huge portfolio

Small agencies often lose confidence here. You don't have a 50-case study library. You've done 8 or 12 relevant projects. That's fine — what matters is how you use what you have.

Choose depth over breadth. One case study that directly mirrors the scope of the contract being tendered is worth more than five that are only loosely relevant. Show the similarity — same type of user, same environment, same type of outcome.

Structure case studies tightly. Most buyers want: the challenge, your role, your approach, the outcome. Keep it to this frame. Don't pad with irrelevant context. The outcome section should include a metric wherever possible — completion rates, cost savings, user satisfaction scores, time-to-service. Even directional data ("reduced form abandonment by 40%") is better than none.

Reference experience held by individuals, not just the company. Named team members with named previous project experience can supplement organisational case studies. If your lead researcher ran a GOV.UK accessibility audit before joining your agency, that's relevant and you can cite it.

Don't pretend to have experience you don't. Evaluators notice when case studies are stretched to cover scope they don't really cover. It creates doubt across your whole response.

Social value: the 20% that agencies underestimate

Social value is consistently weighted at around 10–20% in design and digital contracts, and under the Procurement Act 2023 it's taken more seriously than before. Buyers are now required to monitor and verify delivery of social value commitments after contract award — so vague commitments are increasingly visible as such.

Common mistakes:

• Generic commitments — "we will support local employment" without a specific, measurable action attached
• Commitments that don't relate to the contract — the criteria require social value to relate to the subject matter of what's being procured
• Over-promising — committing to apprenticeships, mentoring programmes, or free training if you don't have capacity or infrastructure to deliver them

What works:

• Specific, time-bound actions (e.g. "we will offer one paid work experience placement of 2 weeks to a local young person during this contract")
• Commitments that connect to the buyer's stated social value priorities (usually published in their social value strategy or commissioning framework — worth reading)
• Commitments you can genuinely deliver and evidence at review points

Pricing pitfalls

The most common pricing mistake in smaller agencies: underpricing to win, then over-running on delivery.

Price for the scope described, not the scope you hope it is. ITTs sometimes have ambiguous scope. If that's the case, price for the clearer interpretation and note the assumption explicitly in your commercial response.

Don't try to win on price alone. Under MAT, price is weighted at 20–30%. If the quality of your response is weak, cutting your day rate by 15% won't save you. Buyers are becoming more comfortable paying for quality where the quality response genuinely justifies it.

Be transparent about day rates. Many public sector buyers use day rate schedules rather than lump-sum pricing. If asked for a day rate breakdown, price honestly — inflated rates that you then discount look suspicious in a panel review.

The single most useful habit: read pipeline notices early

Under the Procurement Act 2023, buyers are required to publish pipeline notices — advance signals of upcoming procurements — before they formally advertise. These give you a meaningful window to research the buyer, understand their context, and in some cases engage through Preliminary Market Engagement (PME) before the ITT lands.

Agencies that start thinking about a bid 2–3 months before the deadline consistently outperform those who pick it up 2 weeks out. Not because they have more resource — because they have more context, better case studies selected, and a clearer sense of what this particular buyer cares about.

Spotting pipeline notices early is exactly the kind of intelligence Tandara is built to surface. If you're spending more than an hour a week scanning procurement portals, you're solving a problem that should already be automated.

Get early tender alerts for your agency — join the Tandara waitlist at tandara.co.uk