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AI Apps

Realistic Numbers for an AI Build

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Build cost by scope

ScopeRangeDuration
Single-purpose tool, one integration£8,000–£15,0004–6 weeks
Document processing with review interface£15,000–£30,0006–10 weeks
Knowledge assistant across systems£18,000–£35,0008–12 weeks
Multi-step workflow with several integrations£30,000–£60,00012–20 weeks

Ranges are wide because integration complexity dominates, and that is knowable only after looking at your systems.

Where the build money goes

  • Integration and data plumbing — frequently 40%
  • The AI pipeline itself — 20–25%
  • Review and correction interface — 15–25%
  • Evaluation, monitoring and failure handling — 15%
The AI is rarely the largest line. Proposals where it is are usually missing the interface or the operational work.

Running cost

Model usage for a typical business application runs £80–£600 a month; hosting adds £40–£200. Higher if you are processing tens of thousands of documents, lower than most people fear otherwise.

We model it against your actual volumes before you commit, and build in a hard cap so a bug cannot produce a surprise.

Maintenance is the line people forget

Twenty to thirty per cent of build cost annually, higher than conventional software because of quality drift. That covers evaluation reruns, threshold tuning, prompt adjustments after provider changes and test set refresh.

Budget it explicitly. Unbudgeted maintenance means an unmaintained system, which means a system nobody trusts within a year.

What makes a quote go up

  1. Systems without APIs, needing import routes or interface automation
  2. Documentation that must be organised before it can be used
  3. Regulatory requirements needing audit trails and retention controls
  4. Multiple document types or languages at launch rather than phased

Frequently asked questions

Can we start smaller?

Usually yes. A £6,000–£9,000 proof on real data answers the feasibility question before committing to a build.

Why is the range so wide?

Because integration complexity varies by an order of magnitude between businesses. A scoping conversation narrows it quickly.

What if the running cost rises?

Alerts at a threshold and a hard cap, with a decided behaviour at the cap. You should never learn about a cost problem from an invoice.

Do you charge for the evaluation work?

It is part of the build. A quote without it is quoting something that cannot be verified.

Keep reading

Trying to budget for an AI project?

Tell us what it needs to do and which systems it touches, and we will give you a range with the assumptions written down.

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