Looking for a list of firms instead? We maintain one here with profiles of the UK companies currently visible in search. This page is the process — how to run the selection, what to ask, and what to put in the contract.
Portfolios all look the same. Case studies are written by the supplier. Testimonials are curated. None of these tells you what you need to know, which is what this firm will be like to work with when something goes wrong.
This is the process we would use if we were buying.
Stage 1 — Work out what you are actually buying
Before contacting anyone, decide which of these you need. They are different purchases with different suppliers.
| You need | Look for |
|---|---|
| A system built and handed over | A custom development firm. Fixed scope, defined handover. |
| Developers to work under your management | A staffing or contract agency. Different commercial model entirely. |
| A product configured | An implementation partner for that product, not a development firm. |
| Advice on what to do | Paid discovery from a development firm, or an independent consultant. |
Most mismatches start here. Hiring a development firm when you wanted staff augmentation, or a development firm when a product partner would have configured something in a fortnight, produces an unhappy project regardless of how good the supplier is.
Stage 2 — Write one brief and send it to exactly three firms
One brief. Identical. Different briefs produce incomparable quotes and you learn nothing from the differences.
Three firms. More than three rarely adds information and costs you weeks.
Your brief needs the problem in business terms with a cost attached, who uses it, what it must achieve as outcomes, what it connects to, your data, your constraints, and what is out of scope. Full structure here.
Include your budget as a range. The argument against — that firms quote up to it — assumes you are powerless, and you are not. Without a budget you get quotes of £15,000, £60,000 and £180,000 because each firm imagined a different project. With one, you get comparable proposals and an honest answer on feasibility.
Stage 3 — Judge the questions, not the pitch
A good firm comes back with questions before a quote. The quality of those questions is the best signal you will get before any money changes hands.
Questions worth hearing:
- What happens when two people do this at the same time?
- What should the system do if that integration is down?
- Who decides when two departments disagree?
- How many of those records are actually active?
- What happens today when this goes wrong?
A firm that quotes immediately with no questions has either built this exact thing before, or has not read your brief properly. Find out which.
A firm that only asks commercial questions — budget, timeline, decision process — is running a sales process rather than a technical evaluation.
Stage 4 — Ask the nine questions
These separate suppliers more reliably than any portfolio. The answers are checkable and they vary enormously.
1. “Do I own the source code outright, and when does it transfer?”
The single most important question on this list. Under UK law, a contractor or agency owns copyright in what they create unless the contract assigns it to you. Paying the invoice does not transfer ownership.
What good sounds like: “Yes, assigned to you on final payment, and here is the clause.”
What should worry you: “You’ll have a full licence to use it.” A licence is not ownership. Full explanation here.
2. “Where will the system run?”
Good: your cloud accounts, your billing, your keys, with access granted to them.
Worrying: their platform. That is a dependency no contract clause removes, and when the relationship ends, so does your system.
3. “Who specifically writes the code, and where are they?”
Not “our team”. Names, locations, seniority. Being sold senior consultants and delivered juniors is a recognised pattern.
If the answer involves an offshore delivery team behind a UK front, that can be perfectly fine — but you should know, because you are then paying a UK rate for it. The real comparison here.
4. “What is your day rate, and how many people are on this?”
Then do the arithmetic yourself:
Quote total ÷ weeks quoted ÷ 5 = implied day rateITJobsWatch reports a median advertised UK contractor day rate of £525 for software developers in the six months to 1 October 2026, London 15–30% higher. A UK agency typically works out at £450–£900 per developer day.
Far below £400? Ask who is writing the code and where. Far above £900? Ask what you are buying beyond engineering.
5. “What happens when your estimate is wrong?”
Every project of size contains a wrong estimate. The useful answer describes a mechanism:
- Fixed price — “that is our commercial risk, you pay the quoted figure”
- Time and materials — “you get a revised estimate before the work happens, with the option of doing less”
“That won’t happen” is not an answer. It means they have not thought about it, or they have and would rather you did not.
6. “Can I take your discovery document to another supplier?”
Good: yes, it is yours.
Worrying: no, or an evasive answer. A discovery document you cannot take elsewhere is a hostage, not a deliverable.
7. “What exactly is in the handover?”
Source code, documentation, deployment instructions, credentials, dependency list with licences, infrastructure access.
Then ask the follow-up: “Could another firm pick this up without you?” A firm that answers comfortably has designed for it. One that becomes uncomfortable has designed against it.
8. “Show me something you built that is still running years later.”
Portfolios show launches. Longevity shows whether the thing was built properly. A system still in daily use after four years tells you more than any screenshot.
9. “What are your prices?”
Most will not say before several meetings. That is information in itself. A firm willing to publish or state a range is a firm confident it is worth the money.
Stage 5 — Verify independently
Companies House — five minutes, free. Incorporation date, filed accounts, directors, and whether there is a trail of dissolved companies at the same address. Worth doing on every supplier you shortlist.
Reviews on platforms they do not control. Google, Clutch, Trustpilot. Testimonials on a company’s own website are curated by definition.
Ask to speak to the engineer who will do the work. Not only the person selling. If this is refused, note it.
Ask for a reference you choose. Suppliers offer their happiest client. Asking to speak to their most recent client, or a project that went through difficulty, produces far more useful information.
Check the website is theirs. A development firm whose own site is slow, broken on mobile or built on a template they clearly did not touch is telling you something.
Stage 6 — Compare properly
Compare what is included, not the total. A cheaper quote excluding discovery, testing, documentation, deployment, training or warranty is not cheaper.
Build this table for all three:
| Firm A | Firm B | Firm C | |
|---|---|---|---|
| Total quoted | |||
| Implied day rate | |||
| Discovery included? | |||
| Testing included? | |||
| Documentation included? | |||
| Training included? | |||
| Warranty period | |||
| IP assignment + trigger | |||
| Hosting — your account or theirs? | |||
| Who writes the code, and where | |||
| Quality of questions asked |
The last row is often the most predictive, and it is the only one that costs nothing to assess.
Stage 6b — Test them with a small piece of work
If the project is large and you are uncertain, buy something small first.
What to buy: discovery, which you want anyway, or a genuinely small piece of standalone work — one integration, one report, one tool.
What it costs: £3,000–£8,000 for discovery; often less for a small build.
What you learn, which no selection process can tell you:
- Whether they communicate when something is unclear, or guess
- Whether estimates hold
- What their written work is like
- How they respond to feedback
- Whether the person who sold it is the person who does it
- What their definition of “finished” is
Why this beats a longer evaluation: a firm’s behaviour under a real deadline with real money is not predictable from meetings, and three weeks of working together tells you more than three months of proposals.
The condition: the small piece must be genuinely standalone, and whatever they produce must be yours. A trial that only works if you continue is not a trial.
Stage 7 — Get the contract right
Insist on these regardless of how well the meetings went.
- Present IP assignment — “are hereby assigned”, not “shall assign”, triggered on final payment
- Source code delivered to a repository you own, from week one rather than at the end
- Handover contents listed explicitly — source, documentation, deployment instructions, credentials, dependency list
- Infrastructure in your accounts, on your billing
- Written change process — how changes are priced, how long a quote takes, who approves
- Acceptance criteria that are testable, not a matter of opinion
- Milestone payments against accepted deliverables — never a large upfront sum with nothing attached
- A warranty period for defects after handover
- Notice period and handover obligation on termination
Warning signs
- Will not discuss cost at any level until several meetings in
- Ambiguous code ownership, or ownership tied to an ongoing contract
- Hosting only on their platform, with no exit route
- A large upfront payment with no deliverable attached
- A fixed price quoted before any discovery — either padded or heading for change requests
- No written change process
- The team on the website is not the team in the meetings
- Pressure to sign quickly. Nothing about custom software is urgent in that way.
- No questions about your data, which is where most overruns originate
The reference call that is worth making
Most reference calls are theatre — the supplier offers their happiest client and you ask whether they were happy. Here is how to get something useful.
Ask for a reference you choose. Specifically: their most recent completed project, or one that went through difficulty. A firm confident in how it handles problems will provide one.
Then ask these, in this order:
- “What went wrong, and how did they handle it?” Something always goes wrong. The answer tells you more than any other question on this list.
- “Was the final cost what you were quoted? If not, why?”
- “How long did it actually take versus the estimate?”
- “What did they tell you that you did not want to hear?”
- “Who did the work, and did you speak to them directly?”
- “How long did they take to respond when something was urgent?”
- “Do you hold the source code and the infrastructure?”
- “If you were starting again, would you use them — and what would you do differently?”
Listen for hesitation rather than content. References rarely say anything damning outright. A pause before “yes, they were good” carries information.
The best question is number four. A client who cannot think of anything a supplier told them they did not want to hear has been sold to rather than advised.
Frequently asked questions
How do I choose a software development company?
Decide what you are actually buying, brief exactly three firms identically, judge the questions they ask before the quotes they give, ask the nine questions above, verify independently via Companies House and third-party reviews, compare inclusions rather than totals, and get the contract clauses right.
What questions should I ask a software development company?
Code ownership and transfer trigger; where the system will run; who writes the code and where; day rate and team size; what happens when an estimate is wrong; whether discovery is portable; what handover includes; something they built that still runs; and what their prices are.
How many software companies should I get quotes from?
Three, with an identical brief. More rarely adds information and costs weeks.
How do I know if a software quote is reasonable?
Divide the total by weeks, then by five, for an implied day rate. UK agencies typically land £450–£900 per developer day against an ITJobsWatch median contractor rate of £525. Well below £400 or well above £900 both warrant a question.
Should I tell suppliers my budget?
Yes, as a range. Without one you receive quotes for three different imagined projects and cannot compare them.
How do I check a UK software company is legitimate?
Companies House for incorporation date, accounts and directors. Reviews on platforms they do not control. Ask to speak to the engineer who will do the work and to a reference you select rather than one they offer.
What should be in a software development contract?
Present IP assignment with a clear trigger, source delivered to your repository, explicit handover contents, infrastructure in your accounts, a written change process, testable acceptance criteria, milestone payments against accepted deliverables, a warranty period, and a handover obligation on termination.
Should I choose a UK firm or offshore?
For most UK SMEs, UK delivery — particularly where requirements will evolve, integration matters, or you do not employ a senior engineer with spare capacity to specify and manage a remote team. The full arithmetic is here.
Written by Jas Singh, Founder. Last updated 8 October 2026. We are a UK custom software development firm and we answer all nine questions above — our prices are published and our handover is specified in full.
Day rate figures from ITJobsWatch UK contract data for the six months to 1 October 2026.
