Custom software company · UK

Custom Software Development Company in the UK

Choosing a custom software company is a commercial decision as much as a technical one. For UK SMEs and scale-ups replacing spreadsheets, Access databases or packages that no longer fit, we give an honest build-or-buy view, a fixed price once the scope is written down, and full ownership of everything we make.

  • Fixed price once the scope is written down
  • Running costs set out before you commit
  • Code, IP and accounts in your name from day one

Who we work with

Who comes to us, and what prompts it.

UK SMEs and scale-ups rarely set out to commission software. Something changes, and the old way stops being safe or affordable.

Owner-managed SMEs

The person who built it is leaving

The colleague who created the spreadsheet or Access database is retiring or moving on, and nobody else can safely change it.

Scale-ups

Growth has outrun the tools

A funding round, a second site or a new product line — and tools that coped with a small team now slow a bigger one down.

Package users

The vendor changed the deal

A steep rise at renewal, a product being retired, or a forced move to an edition that no longer fits how you work.

Service businesses

Customers expect self-service

Clients want to see progress, upload documents and pay online without phoning you — and your competitors already let them.

After a false start

A previous project stalled

A freelancer or agency started the build and did not finish. You need an honest view of what is worth keeping and what it will take to finish.

Regulated SMEs

Auditors want evidence

An inspector, insurer or major client asks who changed what, and when — and the honest answer is that nobody can be sure.

Build or buy

Build or buy, compared over the life of the system.

We would rather lose a project than build something you should have bought. If a package covers your process with little adaptation, it will usually be quicker to roll out and cheaper overall, and the vendor carries the maintenance. Accounting, payroll and a standard CRM are rarely worth building.

The fair comparison runs over several years, not the first invoice: licences for every user, every year, plus the staff time lost to workarounds, set against a one-off build plus hosting and maintenance. In discovery we lay both out side by side using your headcount and the quotes you already have, so the decision is yours and it rests on numbers.

Risk sits on both sides. A package can change its pricing, roadmap or owner under you; custom software needs someone to look after it. Often the best answer is a mix: keep the package for the commodity work, and build only the workflow that is genuinely yours, plus the integrations that stop data being typed twice.

  • Configure what you already own before buying anything new
  • Buy where a package fits with little adaptation
  • Build the workflow that is specific to you
  • Compare costs over several years, not the first invoice

Total cost of ownership

What custom software really costs to own.

The build is the biggest cheque, but not the only one. We set out every running cost in writing before you commit, so any comparison with a packaged product is fair.

The build

A fixed price after discovery, billed against milestones. Discovery itself starts from £2,000 and produces the written scope the price is based on.

Internal tools and workflow systems

Hosting

Servers, database, backups and email sending, on accounts in your name. We estimate the monthly cost for your expected users and data before the build starts.

Support and maintenance

Security patches, framework upgrades, monitoring and small fixes. Software that nobody maintains becomes the next legacy problem.

Support and maintenance plans

Change requests

New features after launch, estimated and approved before any work starts: a small fixed-price project, or flexible hours for lighter changes.

Third-party services

Card payments, SMS, maps, address lookup and e-signatures are charged by their providers. We list each one up front, with how it bills.

Your team’s time

Someone to make decisions, try each sprint’s demo and champion the change. Budget for it — it separates software that gets used from software that does not.

Fixed price and change control

How a fixed-price project actually works.

A fixed price needs a fixed scope, so it comes after discovery, not before. The discovery sprint produces user journeys, a clickable prototype and a written scope with acceptance criteria. The price is set against that document and billed at milestones, each tied to working software you have already seen in a demo.

Change is normal — you will learn things from the demos. When you want something different, we write it up as a change request with its cost and its effect on the timeline, and nothing is built until you approve it. Often a new idea can be swapped for something of similar size that matters less, and the price stays where it was.

What sits outside the fixed price is written down too: third-party fees, hosting, content you supply, and delays while we wait for decisions or access. The aim is simple: you should never receive an invoice you did not expect.

  • Scope and acceptance criteria agreed before the price
  • Milestone billing tied to demos you have seen
  • Change requests costed and approved before any work
  • Exclusions listed in the contract, not discovered later

Choosing a supplier

Warning signs when choosing a custom software company.

Whoever you pick — including us — check for these before you sign anything.

Put these in the contract

Whoever you choose, make sure the agreement covers:

  • Ownership of code, designs and IP passing to your company
  • Repositories and hosting accounts in your name
  • Acceptance criteria for each milestone
  • A written change-request procedure
  • What handover includes if you change supplier

A fixed price after one phone call

Without discovery, a supplier either pads the price to cover what they do not know, or cuts corners later to stay within it.

Your code in their accounts

Repositories, hosting and domains held by the supplier turn every future change — or a move to someone else — into a negotiation.

A platform only they can maintain

Software built on a supplier’s own in-house framework ties you to them. Mainstream technology means any competent developer can pick it up.

Nothing to see until the end

Months of silence, then a big reveal. Fortnightly demos on a staging site you can use are how problems get caught while they are cheap to fix.

Ownership

You own it — all of it.

Custom software should reduce your dependence on a supplier, not create a new one. That includes dependence on us.

Code and intellectual property

Ownership of the code, designs and IP is written into the contract, and the repositories sit in your organisation’s account from the first commit.

Accounts and data

Hosting, domains and third-party services are opened in your name, and your data can be exported in standard formats whenever you need it.

Documentation

Setup and deployment guides, architecture notes and an admin guide — enough for any competent developer to pick the system up.

How we work

From first call to handover.

Our standard seven stages, shown with what you receive and approve at each one — which is where fixed prices and change control either work or fall apart.

  1. 01

    Discovery

    An NDA if you need one, then workshops with the people who do the work. We map the process, the data and the systems it touches, and check what existing products could cover.

    You receive a written scope and acceptance criteria

  2. 02

    Strategy

    Build, buy or both — then a fixed price for the build, split into milestones, with every exclusion and running cost listed.

    You approve the price, milestones and exclusions

  3. 03

    UX & architecture

    A clickable prototype your team tries on real scenarios, and the data model behind it, signed off before development starts.

    You sign off the prototype

  4. 04

    Development

    Two-week sprints with a demo at the end of each and a staging site you can use throughout. Each milestone is billed once you have seen it working.

    You see working software every sprint

  5. 05

    Testing

    Acceptance testing against the criteria agreed in discovery, alongside our automated tests, plus a rehearsal of any data migration.

    You accept each milestone against written criteria

  6. 06

    Launch

    Go-live with your data migrated, short training for your team, and the handover pack: code, accounts, credentials and documentation.

    You hold everything needed to run it

  7. 07

    Optimisation & support

    Optional support for fixes, upgrades and change requests — as a retainer or by the hour — or a clean handover to another team. Nothing ties you to us.

    You choose what happens next

Engagement models

How custom software projects are paid for.

Most custom builds follow the same path: a discovery sprint to write the scope, a fixed-price build against it, then flexible hours for changes and support once the system is live.

Discovery sprint

From £2,000 fixed fee

You have an idea or a problem, but not yet a scope you would trust a quote against.

  • Workshops with your team
  • Prototype or technical spike
  • Written scope, plan and estimate

Flexible hours

From £20 per hour

Fixes, small features and support where the work comes in bursts rather than sprints.

  • Billed weekly for time used
  • Daily written updates
  • No long-term commitment

Prices are in GBP. Every estimate is confirmed in writing after a discovery call — the figures above are where engagements start, not a quote.

Why Techsleight

What working with us is actually like.

No inflated numbers — just how we run projects, and what you can hold us to.

Product engineering, not ticket-taking

We ask what the software is for before we estimate it — and we will tell you when something should not be built, or should be bought instead.

AI where it earns its place

LLM features, retrieval and automation built with evaluation, guardrails and cost controls, and plain software where that is the better answer.

Full-stack under one roof

Design, frontend, backend, mobile, cloud and QA in one team, so nothing falls between suppliers.

UK-focused delivery

UK business hours, estimates in pounds, and a contract with a UK company. Our engineers are based in the UK and India.

Flexible engagement

A fixed-scope project, dedicated developers or a monthly retainer — and you can move between them as the work changes.

You own everything

Code, IP, cloud accounts and documentation are yours from day one. We sign an NDA before discovery if you need one.

Support after launch

We stay on for fixes, upgrades and new features, or hand over cleanly to your in-house team with the documentation to match.

FAQs

Before you choose a software partner.

The commercial side of commissioning software: contracts, pricing, ownership and what happens after launch.

Ask us a question

What should we look for in a UK custom software development company?

Look at how they price and what you will own. A good partner insists on discovery before a fixed price, shows working software every sprint, puts running costs in writing, builds on mainstream technology, and keeps code and accounts in your name from day one. Ask how change requests are handled — it tells you how the relationship will feel mid-project.

What should a custom software contract include?

Ownership of code, designs and IP passing to you; repositories and hosting in your name; a scope with acceptance criteria for each milestone; the payment schedule; a written change-request procedure; what is excluded; how defects found after launch are handled; and what handover includes if you change supplier. We are happy for your solicitor to review ours.

How does a fixed price work if our requirements change?

Every change is written up with its cost and its effect on the timeline, and nothing is built until you approve it. Often a new idea can replace something of similar size that matters less, so the price does not move. What you never get is an invoice for work you did not agree.

What will the software cost to run each year?

That depends on users, data and integrations, so we estimate it for your system during discovery. The usual lines are hosting on your own cloud account, a support and maintenance arrangement, third-party services such as payments or SMS, and change requests as the business evolves. Flexible support starts from £20 an hour.

Why do you charge for discovery before giving a fixed price?

Because a fixed price without a written scope is a guess, and guesses are either padded or cut short later. The discovery sprint, from £2,000, produces user journeys, a prototype and a scope with acceptance criteria — documents that are yours to keep, even if you then build with someone else.

Should we choose a fixed price or pay by the hour?

A fixed price suits a defined build: you know the cost, and change control protects both sides. Paying by the hour suits small, unpredictable work such as fixes and minor features once a system is live. Using both is common — a fixed price for the build and flexible hours afterwards.

Is a freelancer or an in-house developer a cheaper option?

Sometimes. A good freelancer can be the cheapest route for a small, well-defined job, but you carry the key-person risk. An in-house developer makes sense once there is a steady stream of work, though one person rarely covers design, backend, testing and hosting. A team costs more per hour but brings those skills together, with cover when people are away.

Our previous developer controls our code and hosting. Can you help?

Yes — it is a common problem, and usually fixable. We help you recover access to domains, repositories, hosting and third-party accounts, move them into your own name, and review the code so you know what you have. Then you get an honest view on whether to fix, extend or replace it.

What happens if we need to pause or stop the project?

Because the code sits in your repositories from the first commit, pausing or stopping never means losing what has been built. How work in progress is billed is set out in the contract before you sign, and the documentation and accounts are already in your hands.

Do we have to keep paying you after launch?

No. Hosting is billed by the provider to your own account, and support is optional: a retainer, flexible hours, or nothing at all if your own team or another supplier takes over. We would recommend someone keeps security updates current, but it does not have to be us.

Start a project

Choosing a software partner?

Tell us what you use today, what it cannot do and who relies on it. We will reply with an honest view on building, buying or adjusting what you have — and what a fixed-price first version would involve.

  1. 1A senior engineer reads your brief within one working day, and replies with questions or a first view.
  2. 2A 30-minute call to understand the goal, constraints and what good looks like — no sales script.
  3. 3A written proposal with scope, milestones, team and a GBP estimate you can take to your board.

Techsleight Labs is a trading name of Krapton IT Consultancy.

Reply within one working day. NDA on request. Your details are used only to respond — privacy policy.