How much does a business system integration cost in the UK?

Marek Adamczyk · · 7 min read

"How much will it cost to connect our systems?" is usually the first question we're asked, and the honest answer is: it depends on what you're connecting and how. This article explains what drives the cost, gives typical UK price ranges for each approach, and shows how to keep the bill under control.

The short answer

  • Off-the-shelf connector: often a monthly subscription, plus a few days of set-up and testing if your process isn't completely standard.
  • Custom integration of one data flow (for example, closed deals in your CRM becoming invoices in your finance system): typically from around £4,000.
  • Two-way or multi-system integrations with complex mapping: typically £8,000 to £15,000 or more, usually delivered in phases.
  • Ongoing support and monitoring: from a few hundred pounds a month, depending on how critical the integration is.

Those ranges are wide because no two integrations are quite the same. Here's what moves the price up or down.

Three ways to integrate

1. Native or marketplace connectors

Many platforms, including Sage Intacct, QuickBooks and HubSpot, have ready-made connectors. When one fits your process, it's almost always the cheapest and quickest option. The catch is "when it fits": connectors are built for the common case, and struggle with unusual products, tax codes, approval steps or volumes.

2. Integration platforms (iPaaS)

Integration platforms provide pre-built connectors and a visual way to build data flows. Licence costs range from tens of pounds a month for simple automation tools to tens of thousands of pounds a year for enterprise platforms. They're a good choice when you have several integrations to run and want them in one place, but you still need someone to design, build and maintain the flows.

3. Custom integrations

A custom integration talks directly to each system's API and does exactly what your process needs. There's no platform licence, but more design and build effort up front, and you need clear documentation so you aren't dependent on whoever built it.

What drives the cost

  • Number of systems and data flows. Each extra system or flow adds design, build and testing effort.
  • One-way or two-way. Two-way syncs need rules for who owns each field and how to resolve conflicts, which roughly doubles the complexity.
  • Data mapping. Matching customers, products, cost centres and tax codes between systems is usually the hardest part, especially when the data isn't clean.
  • API quality. Well-documented, modern APIs are quicker to work with than older ones or file-based imports.
  • Volumes and timing. Real-time syncs and high volumes need more care with rate limits, retries and performance than a nightly batch.
  • Error handling and monitoring. Alerts, retries and reconciliation add effort, but they're what stops a failed sync going unnoticed for weeks.
  • Security and compliance. Personal or financial data needs least-privilege access, audit trails and careful handling.
  • Migration and cutover. Loading historical data and switching over without disruption takes planning and testing.

The costs people forget

The build is only part of the picture. Budget for:

  • Maintenance. APIs change and old versions are retired; integrations need occasional updates.
  • Monitoring. Someone needs to notice and deal with failures, whether that's your team or a support provider.
  • Licences. Connector or iPaaS subscriptions, and sometimes API access on the systems themselves.

And remember the cost of not integrating. If someone spends two days a month re-keying data between systems, that's around 24 working days a year, before counting the errors and the delays to month-end.

How to keep costs down

  1. Start with the most valuable flow. Integrate the process that wastes the most time or causes the most errors, then build from there.
  2. Use a connector where it genuinely fits. Don't pay for a custom build you don't need.
  3. Agree the mapping early. Decide which system owns each piece of data before anyone writes code.
  4. Clean the data first. Duplicate customers and inconsistent codes make every integration harder.
  5. Build monitoring in from day one. It's far cheaper than investigating a problem months later.

How we price

We keep pricing simple: a free one-hour consultation to understand what you need, an optional integration assessment from £1,500 (deducted from the build if you go ahead), fixed-price builds from £4,000 per integration, and support from £350 a month. Integrations can run in your own environment at no extra cost, or be hosted by us from £60 a month depending on data volume. You'll know the cost before any work starts.