SaaS development in London, from a team that runs its own SaaS products.

A SaaS product is software you sell to many customers from one codebase, so the hard parts are the ones a single-client build never meets: keeping each customer’s data apart, charging them correctly, and knowing what each one costs you to serve.

We build and run two SaaS products of our own, so the lessons here are ones we paid for. Metering belongs in billing from the first commit: when usage is recorded in one place and invoiced from another, the two drift, and the drift is always in the customer’s favour. Every model call should be attributed to a customer and a feature, because AI spend fails quietly and nothing breaks until the invoice arrives. And spending ceilings only count once they have been triggered in production and watched stopping work.

The small model does most of the work. In our own products, moving one high-volume feature from the frontier model to the small one made it several times cheaper and faster with no drop in success. A SaaS product priced per seat has to know those numbers before it sets a price.

We quote SaaS work a phase at a time, each phase fixed against a written scope, so the budget cannot drift and each phase is priced knowing what the last one taught you. Most products start with an MVP and add a second user type, mobile apps or integrations once customers are paying.

All prices exclude VAT. The same figures are on our pricing page.

UK software firms that publish prices put a finished SaaS platform well above a first release. In our survey of published UK prices, Fulminous Software in London quotes SaaS at £30,000 to £150,000 and up, TotalSoft IT Solutions in London starts enterprise SaaS at £60,000, and Jabu Designs puts SaaS-grade builds at £75,000 to £200,000 and up. The consensus range for a multi-tenant, polished, scalable platform is £60,000 to £200,000 and up.

Those figures describe a whole platform bought in one go. We quote a phase at a time, so the first release costs less, and the later phases are priced once you know what your customers actually use.

Read on the firms’ own pages on 14 September 2026. All figures exclude VAT. The full survey, with every source, is in our custom software cost guide.

Onrolo is a recruitment operations platform on web, iOS and Android, in daily use across a national recruitment network. It removes 90 or more hours of manual CV screening per office every month, eight in ten applicants reach a booked appointment, and applicants hear back in minutes instead of days.

GoRizzume is an AI career platform on web, iOS, Android and a browser extension, sold to individuals and licensed to institutions by seat, with cohort reporting for careers teams. It tracks more than 120,000 licensed sponsors, refreshed every day.

Modern, boring, well-supported technology: TypeScript and Next.js on the web, Postgres for data, native iOS and Android where a real app is needed, and hosted infrastructure you can move away from. We use AI tooling to build faster and we validate everything with engineers, tests and real data.

Every build gets cost instrumentation, error monitoring and an audit trail from the first week, because those are the things that are impossible to retrofit and the things that decide whether a SaaS product is still running in year three.

The code, the repositories and the provider accounts, including Stripe and the hosting, are in your name from day one, not on final payment. At each handover you receive documentation, credentials, a runbook and a recorded walkthrough, so another developer could pick the product up without speaking to us. Support is a separate, clearly priced monthly arrangement agreed in the same document as the build.