The short answer
UK AI engagements in 2026 fall into four pricing brackets. Each bracket corresponds to a different scope and a different buyer intent. Knowing which one you are buying saves the discovery call.
The four pricing brackets
| Bracket | Typical price | What you get | Right for |
|---|---|---|---|
| Discovery + audit | £3k to £15k | Written assessment of where AI fits in your business, model-cost projections, build-or-buy recommendation, prioritised roadmap. | Operators who suspect AI helps but want a senior view before committing. |
| Proof of concept | £15k to £60k | A working prototype: chatbot, document Q&A, internal assistant, lead scoring agent. Usually 4 to 8 weeks. Deployed in staging, not yet wired into production. | Teams that want to prove ROI before a full build. |
| Production AI features | £40k to £200k | AI inside your existing software: RAG over your CRM, an AI agent that takes real actions, fine-tuned models, evals, observability, admin dashboard. 8 to 20 weeks. | SaaS scaleups productising AI, mid-market businesses automating real workflows. |
| Ongoing AI retainer | £8k to £40k / month | Continuous prompt engineering, eval maintenance, model upgrades, incident response, new feature shipping. | Operators who already have an AI feature live and need it to keep improving. |
What drives the price
Model layer
Calling any modern LLM via API is cheap to prototype and expensive to operate at scale. A 10k-request-a-day customer support agent on a modern LLM might cost £1.5k a month in inference. Fine-tuning a smaller model on your data is more expensive upfront (£20k to £80k) but creates an asset with predictable unit economics. Self-hosted models are cheaper at huge scale (100k+ requests a day) and otherwise rarely worth the operational cost.
Integration surface
Hooking AI into a single form is small. Hooking it into a CRM with multi-tenant isolation, audit logging, webhook signing, OAuth, and a permissions model is large. As a rule of thumb: integration is 70 percent of the cost, prompt engineering is 20 percent, and the AI model itself is 10 percent.
Safety surface
A customer-facing AI in a regulated industry (finance, health, legal) needs evals, content filters, refusal policies, audit trails, and approval workflows. These triple the build cost compared to an internal-tool use case. If your AI talks to patients, customers, or end consumers, budget at the top of the bracket.
Model upgrades
LLM providers ship new models every 4 to 12 months. Every upgrade requires a re-eval, prompt tuning, and sometimes regression testing against your existing prompts. A retainer budget that does not include upgrade cycles will go over by 20 to 40 percent in year one.
How Nuvenar prices AI engagements
- Fixed-scope, fixed-price: every engagement starts with a written Statement of Work and ends with a fixed-price quote. No hourly invoices.
- Typical project bracket: £25k to £150k for AI-only scope. Larger if combined with software development and DevOps.
- Typical retainer bracket: £8k to £25k a month for AI-only ongoing work. Larger if the retainer also covers application development.
- API costs pass through at cost. If we manage the LLM provider account on your behalf, you see the receipts and there is no markup.
- Senior-only team: every engineer who touches your AI work is senior. No junior layer behind a project manager.
- Production from day one: Nuvenar runs NuvenarHub in production, which means the patterns applied to your build are battle-tested (evals, observability, fallback strategies, prompt versioning, model routing).
How to estimate your project
- Write down the user (who interacts with the AI).
- Write down the action (what the AI does).
- Write down the inputs (what data it has access to) and outputs (what it produces).
- Decide if it is internal or customer-facing.
- Decide if the AI takes real actions or just suggests.
- Decide if you need fine-tuning or off-the-shelf models are fine.
Each of those decisions moves the price within the bracket. The first conversation Nuvenar has with a new AI buyer is exactly this list, written down together in 45 minutes. Book a discovery call and we will scope in real time.
Free tier: NuvenarHub as a starting point
If your AI use case is a WhatsApp auto-reply, AI assistant over your CRM data, call summarisation, or lead scoring, NuvenarHub Pro already includes those at £480 / mo with no bespoke engineering required. Try the 7-day Pro trial before scoping a custom build; in 30 percent of cases the bundled AI does the job and the bespoke project is not needed.