How much does custom software cost in the UK? (2026)

Bespoke software development cost in the UK: the short answer

There is no single price, but published UK figures agree on the order of magnitude. SourceCodeStudio (updated September 2026) says most B2B projects fall between £40,000 and £150,000, with a minimum engagement of £10,000 on its own price list. Magora (London, updated October 2026) publishes bands that sit lower: from £3,000 for a two-week discovery sprint, £10,000–£25,000 for an MVP with one or two core journeys, and £25,000–£60,000 for a production web or mobile platform with backend and admin.

Both are agencies that sell this service, and Magora's bands come from its own estimates. Use them as an order of magnitude, not as a market survey. They are among the most detailed UK price lists in public: they broadly agree at the bottom of the range and diverge at the top, where scope matters more than any table.

A useful rule for reading any figure: every quote is days multiplied by a day rate. A £40,000 tool at the UK contractor median of £525 a day is about 76 developer-days. At £1,000 a day, the level SourceCodeStudio gives for senior architects and AI specialists, it is 40. If a proposal doesn't say where the days go, you have nothing to compare it with.

Every figure in this guide is third-party market data, not a SocketStack price. Magora's bands exclude VAT; check how each quote you receive treats it. For EU quotes: £1 ≈ €1.20 (ECB reference rate, 4 November 2026).

Software developer day rates in the UK

Day rates explain most of the gap between two quotes. IT Jobs Watch tracks the rates advertised in UK contract vacancies. These are its figures for the six months to early November 2026:

• Agencies charge more than contractors because their rate includes project management, testing and margin. Magora puts its own cost per developer-day, including QA and product ownership, at £520–£570, and describes boutique London agencies at £60–£140 an hour and large consultancies at £120–£250 an hour.
• Permanent hire, for comparison: the median advertised salary for a UK software developer is £65,000 a year (IT Jobs Watch, six months to 2 November 2026), before employer costs. One person rarely covers design, backend, mobile and testing.
• Nearshore, for comparison: Spanish boutique studios publish €60–€120 an hour (≈ £50–£100) and large consultancies €150–€350 (≈ £125–£290), according to Duotach, a Spanish agency (June 2026; order of magnitude). More on that model in nearshore software development from Spain.

What drives the cost of custom software

Two projects that sound the same in one sentence can differ by a factor of two. These are the factors that weigh most, roughly in order of impact:

• Integrations. Connecting to Xero, Sage, your CRM, your online shop or your bank. SourceCodeStudio reports quotes for the same project varying by £20,000 on integrations alone. A documented API is quick; nightly CSV exports and workarounds are not.
• Business rules and exceptions. The standard flow is quick to build. The expensive part is the trade customer with special pricing, the order that splits across two depots, the approval that changes above a certain amount.
• Users, roles and permissions. Everyone seeing everything is cheap. Each role seeing only its own data, with an audit trail of who changed what, takes longer.
• Data migration. Moving years of spreadsheets or an old Access database into the new system, cleaning duplicates on the way, can be a project inside the project.
• Design. SourceCodeStudio quotes £4,000–£10,000 of UI design for an internal tool and an extra £15,000–£35,000 when the software faces your customers.
• Regulated sectors. Builds in finance, health and similar sectors cost roughly 25–50% more than non-regulated ones, according to the same source, because of security, audit and documentation.
• Mobile and offline. A phone app on top of the web platform, or one that must work without signal, adds a second front end. We break it down in how much it costs to build an app.
• The scope of version one. The lever you control most. A first version that solves one process well costs a fraction of one that tries to replace everything at once.

Custom software cost by project type

Bands published by UK agencies in 2026. Where two sources give different figures for similar work, both appear. A dash means the source gives no timescale.

• How to read it: find your row, then move within the range using the factors above. Several integrations or a heavy data migration push you to the top.
• What it leaves out: hosting, third-party licences and maintenance, covered in the next section.

Hidden costs: what the first quote often leaves out

The build is only part of the total cost of ownership. Ask for each of these in writing before you sign:

• Maintenance. SourceCodeStudio puts support and maintenance at 15–25% of the build cost a year: £9,000–£15,000 a year for a £60,000 project. Magora's retainers start from £1,000 a month. Ask what's included: fixes, security updates, small improvements and response times. See software maintenance and support.
• Hosting and infrastructure. Servers, database, backups and monitoring. SourceCodeStudio gives £200–£500 a month as typical on Azure or AWS after launch, within a wider £100–£2,000 across project sizes. Ask whose name the cloud account is in.
• Third-party licences. Maps, email and SMS sending, e-signature, payment gateways, paid ERP API tiers. Usually billed by usage and outside the development quote.
• AI API usage. If the software uses language models, every document or conversation has a variable cost. We work it out with official prices in the cost of implementing AI in a business.
• Your team's time. Someone has to explain the process, review demos and test with real data. It isn't an invoice, but it's hours to plan for.
• Change requests. Whatever is added mid-project. On a fixed price it's quoted separately; on time and materials it simply adds to the bill.
• Five years, not one. SourceCodeStudio estimates the five-year cost of a £60,000 build at £130,000–£180,000 once support, hosting and improvements are added. Compare that figure, not the build price, with a SaaS subscription.

Bespoke or off-the-shelf: when paying for development makes sense

Before asking for quotes, check whether a product already does the job. If a SaaS tool, a module of your ERP, a low-code platform or a well-built spreadsheet covers 90% of what you need, it's usually cheaper and faster. We'd tell you so.

Bespoke pays off when the way you work is an advantage you don't want to bend to a tool, when systems that don't talk to each other cost hours every week, or when per-user licences grow with every hire. Do the sum with your own numbers: users × price per user × 12 months × five years, against the build plus 15–25% a year in maintenance.

If the problem is a spreadsheet that has outgrown itself, start with converting Excel to a web app. If it's several tools that don't share data, ERP and CRM integration may be enough without building anything new.

How to compare custom software quotes: checklist

Two quotes are only comparable if they describe the same thing. Before you look at the total, check that each proposal answers these:

• Written scope: which functions are in and, above all, which are out.
• Pricing model: a fixed price or an estimate of days? If it's days, is there a cap? We compare both in fixed price vs time and materials.
• Changes: how they're priced and who approves them before work starts.
• Schedule: delivery dates in writing, and how often you'll see working software.
• Code ownership: whose name the repository is in, and whether the contract assigns the intellectual property to you in writing. Our guide to fixed price vs time and materials covers what that clause should say. Check it with your solicitor.
• Accounts and infrastructure: cloud, domains and third-party services, ideally in your company's name.
• Acceptance criteria: how you'll agree that something is finished.
• Support: what maintenance covers, what it costs and the response times.
• Exit: documentation and handover if you change supplier.
• Your side: what the supplier needs from you (access, data, decisions) and by when.

Common mistakes when asking for a quote

• Comparing only the total. The cheapest quote often leaves out the data migration, the admin panel or testing.
• Putting everything in version one. It's what drives cost and delay most. Better a useful version in weeks, then grow.
• Forgetting years two to five. 15–25% a year in maintenance changes the comparison with a SaaS subscription.
• Accepting days without a cap or reporting. If you pay by the day, you need regular timesheets and an agreed ceiling.
• Leaving code ownership until there's a dispute. Paying the invoice doesn't by itself transfer the copyright.
• Briefing three suppliers differently. Send each one the same written brief, or you'll be comparing three different projects.

How SocketStack works

We start with a free 30-minute call and, if the project is worth building, give you one fixed price per project, a working demo every two weeks and the code in your company's repository from day one. The detail, including how changes are handled, is in how we work.