Choosing a web development company is a five-figure decision you'll live with for years. Get it right and you have a partner who ships, communicates and stands behind their work. Get it wrong and you inherit buggy code, missed deadlines and a relationship that ends in lawyers.
This checklist gives you ten things to verify before you sign anything — plus the red flags that should send you walking. Use it for every agency you shortlist, and compare them on the same criteria.
1. Relevant portfolio, not just pretty screenshots
Ask to see work similar to yours — not just visually, but functionally. A portfolio of brochure sites tells you nothing about an agency's ability to build your booking platform or customer portal. For each relevant project, ask: what did they actually build, what was their role (design only? full build?), and is it still live and working?
Then go further: ask for a reference you can call. Any agency can show screenshots; the serious ones will connect you with a past client who'll tell you what the process was really like — including what went wrong.
2. Technical competence you can verify
You don't need to be a developer to assess technical quality, but you do need to ask the right questions:
- What stack will they use, and why? "Whatever you're comfortable with" is not an answer. They should recommend a stack with reasons tied to your project — and be able to explain the trade-offs in plain English.
- Who actually writes the code? Senior developers, juniors supervised by seniors, or an outsourced team you've never met? All are legitimate at different price points, but you should know which you're buying.
- What's their testing approach? If the answer is "we test as we go" with no mention of test plans, staging environments or QA process, expect bugs in production.
- Can they show you code quality? Ask about code reviews, coding standards and version control. A professional team does all three as a matter of routine.
3. A process they can describe
Ask them to walk you through how a project runs, week by week. You're listening for structure: discovery, design sign-off, development sprints, testing phases, deployment. Vague answers — "we're agile, we just get on with it" — usually mean there's no process, and no process means your project is managed by hope.
Specifically, ask: how often will we speak? What does a typical sprint review look like? How are changes handled? What happens if we disagree on scope? The answers matter less than the fact that they have answers.
4. Honest estimation, not comfortable numbers
Refer back to our guide on estimating a web app project: the estimate tells you everything about the agency. Look for a breakdown by phase, an explicit assumptions list, stated exclusions, and caveats where there's genuine uncertainty. Be suspicious of the quote that's dramatically cheaper than the others — it signals misunderstood scope, not efficiency.
Also ask what happens when the estimate is wrong. Every project hits surprises; the professional answer involves early flagging, options, and shared decision-making — not silent corner-cutting or surprise invoices.
5. Communication and cultural fit
You'll work with this team for months. In the sales process, notice: do they listen or pitch? Do they ask about your business or just your features? Do they explain things clearly or hide behind jargon? The sales experience is the best preview of the project experience you'll get.
Practical checks: who's your day-to-day contact (not the salesperson — the project manager or lead developer)? What timezone are they in, and what are their working hours? How quickly do they respond during the sales process? Slow responses now mean slow responses when your site is down.
6. Post-launch support and maintenance
Launch day is the middle of the story, not the end. Ask what's included after go-live: bug-fix warranty period (30–90 days is standard), ongoing maintenance plans, response times for critical issues, and who hosts and monitors the site.
An agency with no maintenance offering is telling you they don't want to be responsible for their own work in production. That's worth knowing before you sign. Maintenance isn't an upsell — as we explain in our article on why website maintenance matters for online sales, it's what keeps your investment working.
7. Ownership: code, data and IP
This one gets people. Confirm in writing: you own the code, the design and the IP upon final payment. Check who owns the hosting accounts, domain registrations, and third-party service accounts (they should be in your name, not the agency's). Ask what happens if you part ways — can another developer pick up the codebase? Is there documentation?
Agencies that hold your domain or hosting hostage, or that build on proprietary systems you can't leave, are creating lock-in. Sometimes that's fine if you go in with eyes open; it's a disaster if you discover it during a dispute.
8. Security and compliance practices
Ask how they handle security: HTTPS everywhere (non-negotiable), secure handling of user data, GDPR-compliant data practices, and what happens in a breach. If your site takes payments or stores personal data, ask about their experience with PCI DSS considerations and data protection impact assessments.
You don't need a security audit of the agency — you need evidence they think about security as part of the build, not as an afterthought. "We've never had a problem" is not a security policy.
9. Realistic timelines
An agency that promises your complex platform in four weeks is either not listening or not honest. Realistic timelines include contingency — because third-party APIs go down, feedback rounds take longer than expected, and content always arrives late. Ask what's built into the timeline for slippage, and what happens to the schedule when you (inevitably) take two weeks to approve designs.
Also ask about their current workload. An agency that's clearly overcommitted will deprioritise your project the moment a bigger client shouts. You want a team with capacity, not just capability.
10. Commercial terms in plain language
Read the contract. Key clauses: payment schedule (tied to milestones, not calendar dates), intellectual property transfer, termination rights for both sides, liability caps, and what "done" means (acceptance criteria). If the contract is heavily one-sided or the agency resists reasonable amendments, that's information.
Payment structure tells you about confidence: milestone-based payments (e.g. 25% upfront, 25% at design sign-off, 25% at beta, 25% at launch) align incentives. Demands for 100% upfront do not.
Red flags: walk away when you see these
- No questions about your business. If they quote without understanding what you're trying to achieve, they're selling hours, not outcomes.
- Guaranteed rankings or traffic. Nobody can guarantee Google rankings. Anyone who does is either lying or planning to use tactics that will get you penalised.
- They badmouth every previous client. If all their past clients were "difficult", the common factor isn't the clients.
- No portfolio you can verify. "We signed NDAs for everything" is sometimes true and usually convenient. At least some work should be demonstrable.
- Pressure tactics. "This price is only valid until Friday" is a sales technique, not a project methodology. Professional agencies don't need it.
- They'll build anything, no pushback. A good development partner challenges your ideas. One that agrees with everything is either not thinking or planning to bill you for the rework later.
- Offshore without transparency. Outsourcing isn't inherently bad, but undisclosed outsourcing — where you think you're hiring a Manchester team and your code is written overnight by strangers — is a trust problem.
Making the final decision
Score each shortlisted agency on the ten points above. Don't just go with the cheapest, and don't just go with the slickest pitch — go with the team that asked the hardest questions, gave the most honest estimate, and showed you work they'd be proud to defend.
Then start small if you can. A paid discovery phase or a small initial milestone is a low-risk way to test the working relationship before committing to the full build. How an agency handles a £5,000 discovery tells you exactly how they'll handle a £100,000 project.
Choosing a development partner is one of the highest-leverage decisions in a digital project. Take it seriously, use the checklist, and trust the evidence over the sales patter. For a related perspective on selecting software partners more broadly, read our guide to choosing a software development company.
If you'd like to put us through this checklist, we'd welcome it — our website development team works to these standards on every project, and we're happy to provide references, walk you through our process, and give you an honest estimate with the assumptions shown. Contact us to start the conversation.
FAQs
How many web development companies should I get quotes from?
Three to five is the sweet spot. Fewer and you can't calibrate; more and you'll drown in sales calls. Make sure at least one is a company whose work you already admire, and compare all of them against the same checklist — not just on price.
Should I choose a local UK agency or can I work remotely?
Remote works fine for most projects if the process is strong — regular calls, shared project tools, clear milestones. Local matters more when you want face-to-face workshops or when timezone overlap is critical. What matters most isn't geography; it's communication quality and accountability.
What's more important: portfolio or process?
Both, but process predicts your experience better than portfolio predicts the outcome. A beautiful portfolio with no process behind it means your project depends on luck. Ask about process first, then verify it against the portfolio and references.
How do I check a web development company's technical quality?
Ask about their stack choices and the reasoning, who writes the code, their testing and QA process, code reviews and version control. Then ask for a client reference and ask that client specifically about bugs, deadlines and how problems were handled. Past behaviour is the best predictor.
What should a web development contract include?
Milestone-based payment schedule, IP transfer on final payment, termination rights for both parties, acceptance criteria defining "done", a bug-fix warranty period, and clarity on who owns hosting, domains and third-party accounts. If any of these are missing or one-sided, negotiate before signing.
