How much does custom software
cost in the UK?
Published planning ranges, an editable delivery-cost calculator and the questions that turn a broad budget into a credible first-phase estimate.
Use market ranges to find the order of magnitude.
Current UK agency guides commonly place a focused internal tool or small custom application around £15,000–£50,000, a connected business system around £50,000–£150,000, and a complex or enterprise platform around £150,000–£500,000+. Those bands are useful for early planning, but they are not interchangeable quotes.
The ranges are a synthesis of published UK guidance from Make IT Simple and Seven Solvers, reviewed on 14 July 2026. They describe the market, not ORBN’s pricing.
Focused tool or first release
One bounded workflow, modest role model and limited integration or migration. It should still be usable, monitored and supportable.
Connected business application
Several roles or workflows, meaningful existing-system integration, operational reporting and a managed rollout.
Platform or major modernisation
Multiple domains, large migration, high assurance, phased replacement or a system that must serve many teams and channels.
If the scope begins with an existing critical application, use the legacy system modernisation risk assessment before estimating a replacement programme.
Figures exclude VAT and should be treated as broad 2026 UK planning bands.
Before estimating a build, use the custom vs off-the-shelf decision scorecard to test whether custom software is the right starting point.
Custom software cost estimator.
A supplier may structure its price differently, but delivery effort still comes from people contributing over time. Use this model to challenge team, duration, rate and uncertainty assumptions in any proposal.
Change every input. The starting values illustrate a focused first release; they are not ORBN rates or a project quote.
Formula: people × weeks × average days × blended day rate, plus the chosen delivery allowance.
Excludes VAT, third-party licences, cloud consumption, hardware, data purchases and post-launch support. Use it to test assumptions, not to approve a supplier or budget.
The six cost drivers behind the screens.
Counting features hides the expensive parts. Ask what the software must connect, preserve, prove and recover from.
Workflow and edge cases
The normal path is usually cheap to describe. Exceptions, approvals, reversals, permissions and manual judgement determine how much behaviour the software must safely encode.
Systems and integrations
A documented API is different from a legacy database, scheduled export or vendor-controlled interface. Reliability, retry and reconciliation requirements also belong in the estimate.
Data and migration
Cleaning duplicate records, mapping old fields, preserving history and proving totals can consume more effort than moving the data itself.
Users and experience
One internal desktop workflow differs from customer web, warehouse mobile, offline field and accessibility needs across several roles and devices.
Security and assurance
Identity, access control, audit trails, resilience, penetration testing, regulatory evidence and recovery targets change both implementation and verification effort.
Release and operating model
Parallel running, training, support hours, hosting ownership, monitoring and vendor handover affect the work needed to make software dependable after the first release.
A credible quote includes more than coding.
Discovery and delivery boundary
Process mapping, technical investigation, value baseline, release boundary, assumptions and explicit exclusions.
Design and architecture
User flows, data model, security boundaries, integration contracts and the operating shape needed to support the release.
Build and integration
Application behaviour, interfaces, data movement, permissions, automation and the infrastructure used to run them.
Quality and acceptance
Automated and exploratory testing, performance, security checks, representative data and acceptance against real operational scenarios.
Release and adoption
Migration, parallel running, monitoring, documentation, training, support readiness and a safe rollback or recovery path.
Match commercial structure to uncertainty.
Fixed phase
Useful when the outcome and acceptance boundary are understood. Check how assumptions, change and supplier-caused rework are handled.
Time and materials
Useful when priorities will evolve. Require visible throughput, working software, budget checkpoints and authority to stop or redirect.
Dedicated capacity
Useful for a continuing product roadmap. Clarify team composition, availability, ownership, handover and what happens when demand changes.
Four useful ways to reduce the first investment.
Choose one complete workflow
A narrow release can still move a real order, case or decision from start to finish. Avoid a broad collection of half-built screens.
Keep reliable systems of record
Integrate a dependable finance, CRM or ERP platform instead of rebuilding commodity capability without a business reason.
Bring real exceptions early
Representative data and awkward cases expose uncertainty while the release boundary can still change cheaply.
Measure before and after
Baseline time, corrections, delays, service impact and vendor cost so the next phase competes for investment on evidence.
Custom software quote checklist.
The first release and its acceptance tests are written in operational language.
Assumptions, exclusions, third-party costs and client responsibilities are explicit.
Integrations name the source of truth, failure handling and vendor dependencies.
Migration includes reconciliation, representative test data and rollback decisions.
Security, environments, monitoring, backups and recovery have named owners.
Code, data, intellectual property, hosting access and handover terms are unambiguous.
Post-launch support and change are separated from the initial delivery budget.
There are budget checkpoints tied to working software and permission to stop.
Price the workflow on both sides of the decision.
Compare the delivery and operating cost with the repeated value available: staff time returned, errors avoided, vendor fees retired, capacity released, service improved or revenue enabled. Keep uncertain benefits separate from savings that already appear in the accounts.
Annual value ÷ total first-year cost
Use a range, record the assumptions and include operation—not only the build. This is a comparison tool, not an ROI guarantee.
A working day reduced to 20 minutes
ORBN’s route optimisation project delivered a reported saving of more than £36,000 per year. The project price is not published, so no invented payback claim is made.
Read the measured case studyCustom software cost, explained.
How much does custom software development cost in the UK?
Published UK agency guides commonly place focused tools around £15,000 to £50,000, connected business systems around £50,000 to £150,000, and large or enterprise platforms from roughly £150,000 to £500,000 or more. These are broad market planning bands, not ORBN prices. The useful estimate comes from the delivery team, duration, integration, data and assurance required for a defined first release.
Why do custom software quotes vary so much?
Two projects with similar screens can contain very different work. Existing-system access, data quality, permissions, migration, offline behaviour, audit requirements, performance, edge cases and rollout risk often affect cost more than the visible feature list.
Can a bespoke software project start small?
Yes. A bounded first phase can prove a difficult integration or remove one repeated workflow before a wider platform is approved. Starting small works when the phase is genuinely usable and its outcome can be measured, rather than being an isolated demo that must be rebuilt.
Should custom software be fixed price or time and materials?
Fixed price can suit a well-understood, bounded phase. Time and materials or a capacity model can suit evolving product work where learning changes the priority. A hybrid often fixes discovery or the first release, then uses an agreed team and review cadence for subsequent changes.
What costs continue after launch?
Plan for cloud or hosting, monitoring, security updates, backups, third-party licences, support, incident response and ongoing product changes. Some are predictable subscriptions; others depend on usage and service level. A quote should separate these from the one-off delivery budget.
Is the calculator an ORBN quote?
No. It is a transparent arithmetic model using assumptions you control. It excludes VAT, third-party costs and post-launch operation. A project quote requires a defined workflow, delivery boundary, risks and acceptance criteria.
One workflow.
Assumptions on the table.
Bring the process, its current cost and the systems it crosses. We will help define a useful release boundary and explain what would drive the delivery budget.