How much does custom software cost in the UK?
A focused system that replaces one process costs £5,000 to £12,000. A departmental system with several user types and a couple of integrations runs £12,000 to £35,000. Organisation-wide platforms start around £35,000 and go up from there.
What follows is where those numbers come from, the arithmetic that decides whether bespoke beats a subscription, and what to ask before you accept any quote.
By Lucas Reddington, full-stack developer and AI engineer, Northbytes. Last updated .
What bespoke systems cost, by scope
Nobody buys "custom software"; they buy a specific system that does a specific job. These four bands cover most UK projects, and the thing that decides which one you're in is almost always how many different kinds of person use it.
One process, one team
£5,000 - £12,000
Replacing a departmental spreadsheet: records, forms, permissions, exports, a dashboard.
One or two kinds of user, a single workflow, a proper database behind it. This is where most first bespoke systems sit, and where the return is easiest to prove.
Departmental system
£12,000 - £35,000
Booking and scheduling, case management, a customer database with staff and admin roles.
Several user types with genuinely different permissions, reporting that matters to someone senior, and usually one or two integrations with tools you already pay for.
Organisation-wide platform
£35,000 - £100,000
An MIS, an operations platform, or a system your customers log into as well as your staff.
Multiple connected modules, external users, real data volumes, and the migration of one or more legacy systems. Usually delivered in phases, not in one go.
Regulated or mission-critical
£100,000+
Healthcare, finance, safeguarding, or anything where downtime stops the organisation.
The cost is in assurance, not features: formal testing, audit and retention requirements, data residency, accessibility standards and resilience work.
Two worked examples, with the assumptions stated
Ranges are only useful next to a real scope, so here are two, priced as we would price them. Both are illustrative examples, not quotes for a named client, and both assume you supply the content and we do the data migration.
Replacing one departmental spreadsheet
around £5,000 - £7,000
About a dozen staff, one kind of record, two roles: everyone can read and add, a supervisor can approve and delete. A records list with search and filters, a form with proper validation, file attachments, CSV export, a dashboard with the four numbers management asks for every month, an audit log of who changed what, and migration of the existing workbook including cleaning the inconsistent bits.
Assumptions: no integrations with other systems, no external users, no formal accessibility audit, hosted with us at £90 a month because it has a database. Six to eight weeks.
A booking and scheduling platform
around £14,000 - £20,000
Three kinds of user: customers who book and manage their own appointments, staff who manage availability, and an administrator. Calendar logic including cancellations and rescheduling, email and SMS reminders, Stripe payments with refunds, a staff rota view, reporting, and an audit trail covering every change to a booking.
Assumptions: one payment integration and one calendar integration, no accounting-system sync, English only, migration of an existing customer list. Ten to fourteen weeks.
What moves the price
In rough order of how much they matter to a quote. If you want to bring a number down, this is the list to negotiate against.
How many kinds of user
The single biggest driver. Each distinct role means its own permissions, its own screens and its own testing. A system for one team is a fraction of one serving staff, customers and an outside partner.
Integrations
Every external system is a small project: accounting, CRM, payment processor, calendar, single sign-on. Well-documented modern APIs are straightforward; a legacy system with no API is where budgets go to die.
Data migration
Rarely the bottleneck people expect, and often the one they didn't. Twenty years of a spreadsheet with inconsistent formats needs cleaning as it moves, and that is real work.
Reporting and dashboards
A list with filters is cheap. Cross-cutting analytics over large datasets, scheduled reports and exports that match a regulator's format are not.
Compliance and audit requirements
Full audit trails, retention rules, data residency and access reviews all add work. They are also usually non-negotiable, so they belong in the first quote, not in a later surprise.
Design and usability
An internal tool for fifteen trained staff can be plain. Something a thousand customers use unaided needs design work, and it pays for itself in support calls you never receive.
The arithmetic behind any quote
Almost every price in this industry is days multiplied by a rate, even when it's presented as a fixed figure. UK day rates run from roughly £250 for a freelancer to £700 for a small studio, £900 or more for a mid-sized agency, and well past £1,200 for a consultancy. A twenty-day project is therefore £5,000 or £24,000 depending entirely on who you asked.
That's why "how much does custom software cost" has no single answer, and why comparing two quotes means comparing days and scope, not totals. Ask any supplier how many days they've allowed and for what, and the conversation gets useful immediately.
Our prices sit below the studio range for a specific and boring reason: our developers use current AI tooling for the mechanical parts of the work, so fewer days are spent on scaffolding and more on the decisions. Every line is still reviewed and owned by an engineer, and the quote is fixed, so if a build takes longer than we thought that risk is ours.
Bespoke versus subscriptions, over five years
The comparison people rarely do properly. Take a per-seat SaaS tool at £30 a user a month. Ten users is £3,600 a year, or £18,000 over five. A hundred users is £36,000 a year, or £180,000 over five, and that figure rises every time you hire.
A bespoke system at £15,000 with £1,000 a year of hosting and maintenance is £20,000 over the same five years, and it costs the same whether ten people or a hundred use it. So the crossover depends almost entirely on headcount and time horizon: below about ten users on a standard process, SaaS usually wins; above thirty, bespoke usually does.
What that arithmetic misses on both sides: SaaS includes support, updates and someone else carrying the risk, which is worth real money. Bespoke includes fitting your process exactly, and the cost of the workarounds you're currently doing by hand is rarely on anyone's spreadsheet. The bespoke versus off-the-shelf guide works through that decision properly.
A checklist for reading a quote
- Is this fixed or an estimate, and what happens if the work runs over?
- What is explicitly excluded? The exclusions tell you more than the inclusions.
- Who owns the code, the data and the hosting accounts on delivery? Get it in writing.
- Is data migration in the price, or a separate line later?
- What does year two cost: hosting, maintenance, support response times?
- What happens if we want to leave? A documented export and a clean handover, or a conversation you'd rather not have?
- Can we see something you've built and run, not a portfolio screenshot?
Ours, for the record: PolicyMind is a live compliance platform we built and run, with several user types, an approval workflow and the audit evidence an inspection asks for. And our answers to the ownership questions are on the custom software page, written as a handover checklist instead of a promise.
Rough it out in thirty seconds
Answer four questions and see a range, plus which answers moved it. It is a planning aid built from our published prices, not a quote - the real number is fixed and agreed before anything starts.
Likely range for this shape of project
£5,000 – £8,000
Then £90 a month: hosting and maintenance for an app with a database.
What moved the number
Nothing yet - this is our published starting point. Covers a focused system with one or two kinds of user, a proper database, logins, an audit trail and migration of existing data.
Assumes a UK-based team, no regulated-sector requirements, and that you own the result. The spread is real: the same brief lands differently once we have seen the actual data and the actual systems. Anything genuinely unusual we would rather scope properly than guess at.
Get the fixed numberCommon questions
How much does custom software cost in the UK?
A focused system replacing one process starts around £5,000 to £12,000. A departmental system with several user types and a couple of integrations runs £12,000 to £35,000. Organisation-wide platforms start around £35,000 and regulated or mission-critical systems go beyond £100,000. Our own starting point is £5,000, on a fixed quote agreed before any code is written, and we usually propose a first phase that replaces the most painful part of your process rather than everything at once.
Is custom software cheaper than paying for SaaS?
Over five years, often yes, but not always, and the honest answer depends on your headcount. Per-seat SaaS at £30 a user a month costs £18,000 over five years for ten users, and £180,000 for a hundred. A £15,000 bespoke system with £1,000 a year of maintenance costs £20,000 over the same period regardless of how many people use it. So bespoke wins on larger teams, on long time horizons, and where the off-the-shelf tool doesn't quite fit. SaaS wins on small teams, on standard processes and where you want someone else carrying the risk.
Why do development quotes vary so much?
Day rates across the UK range from roughly £250 to £1,200 depending on whether you're buying a freelancer, a small studio, a mid-sized agency or a consultancy. On top of that, two suppliers reading the same brief will have imagined different systems, and the cheaper quote has usually imagined the smaller one. Ask for the feature list, the assumptions and what is explicitly excluded, and most of the apparent difference turns out to be scope, not value.
What does it cost to run and maintain each year?
Budget 15 to 20 percent of the build cost per year for maintenance, plus hosting. That covers dependency and security updates, small changes, and the work of keeping up with browser and platform changes. Our hosting and maintenance is £45 a month, or £90 with a database, with bug fixes included rather than quoted separately. A system with no maintenance budget is not saving money; it is accumulating a rebuild.
Can we start small and add to it later?
Yes, and it is what we usually recommend. Pick the single most painful part of the current process, replace that, and let the system prove itself before you fund the next phase. It gets value in front of people in weeks rather than months, it surfaces the requirements nobody thought to mention, and it means a project that stalls has still delivered something useful instead of nothing.
Sources
Figures quoted from outside Northbytes come from these sources, checked on 26 July 2026. Our own prices are our published rates.
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