The verdict in three sentences
For a contractor answering 120 tenders a year, the quality submission is the bottleneck: 2 to 3 days per bid, often written under pressure by the same person. A private AI assistant, fed with your winning bids, project case studies and quality procedures, costs between 15,000 and 40,000 GBP in 2026 plus 50 to 300 GBP a month in API usage, and halves drafting time. The realistic goal is to move from an 18% to a 25% win rate by spending the saved time on reading the brief, always with human review.
Why quality submissions cost so much
In London public sector construction frameworks, quality often weighs 40 to 70% of the final score, alongside social value questions. Each response must answer the invitation to tender method statement questions: methodology, resources, programme, waste, health and safety, carbon reduction. Three quarters of the content can be reused from one bid to the next, but it has to be found, adapted and reformatted.
| Bid step | Current time | With AI assistant | What the AI does |
|---|---|---|---|
| Reading the ITT and specification | 3 to 4 h | 1 to 1.5 h | Extracts criteria, weightings, requirements |
| Finding past content | 3 to 5 h | 15 min | Retrieves relevant passages |
| Drafting methodology and resources | 6 to 8 h | 3 to 4 h | First draft tailored to the project |
| Programme, waste, health and safety | 3 to 4 h | 1.5 to 2 h | Proposes a structure to complete |
| Formatting and review | 2 to 3 h | 2 h | Checks compliance with the ITT |
| Total per bid | 17 to 24 h | 8 to 10 h |
Across 120 bids, this frees about 150 working days a year for the bid team, close to one full-time role.
Budget, architecture and confidentiality
The assistant relies on retrieval from your own document base (a technique called RAG): bids and case studies are indexed in a private space, and the language model drafts only from those sources, citing the passages used. No data trains a public model if the API contract is chosen correctly.
| Item | 2026 market budget (GBP, ex VAT) | Note |
|---|---|---|
| Scoping and ingesting 80 to 150 past bids | 3,000 to 7,000 | Cleaning, tagging by sector and client |
| Document base and search engine | 4,000 to 10,000 | UK or EU hosting |
| Drafting interface and templates | 5,000 to 15,000 | Word export in company branding |
| ITT compliance checker | 3,000 to 8,000 | List of requirements covered or missing |
| Total project | 15,000 to 40,000 | 6 to 10 weeks |
| Language model API | 50 to 300 per month | Depends on bid volume |
| Maintenance and updates | 200 to 600 per month | New bids indexed |
Three safeguards are essential. Project references and figures (headcount, plant, durations) must come from the base and never be invented. Every bid is reviewed and signed off by a manager. Client documents stay in the private space, in line with UK GDPR and tender confidentiality clauses.
Mini case study
Sarah, bid manager at a 90-person groundworks and frame contractor in east London, answers 120 tenders a year. Illustrative scenario: project at 28,000 GBP, API and maintenance at 500 GBP a month, i.e. 34,000 GBP in year one.
Time saved: 120 bids x 12 hours = 1,440 hours at a loaded cost of 50 GBP, i.e. 72,000 GBP. Commercial effect: with an average contract of 400,000 GBP and a 5% net margin, moving from 18% to 22% in year one means about 5 extra contracts, i.e. 100,000 GBP of margin. Counting only time saved, the project pays back in 5 to 6 months.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
FAQ
How much does an AI bid writing assistant cost in 2026?
Budget 15,000 to 40,000 GBP ex VAT for setup, then 50 to 300 GBP a month in API usage and 200 to 600 GBP in maintenance. Price depends mostly on the number of past bids to ingest and the compliance checker.
Can the AI invent project references?
That is the main risk with consumer tools. A well-built assistant drafts only from your documents, cites sources and flags missing information instead of making it up.
Are our documents protected?
Yes, with UK or EU hosting, an API contract excluding training on your data and named user access. Client tender packs stay in your private space.
Will our win rate necessarily increase?
No, AI frees time, it does not win contracts alone. Firms that improve, often by 4 to 7 points, reinvest saved hours in criteria analysis and site visits.
How many past bids do we need to start?
About fifty recent bids is enough, ideally with their quality scores to identify the highest-rated passages.
Let's scope your project. Send us your annual tender volume, sectors and a few sample bids: we will price a scope, an indicative GBP budget and a go-live date. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
