What to Ask Before Hiring a SaaS Development Company

Commissioning a custom SaaS platform is one of the biggest commercial decisions a UK business owner can make. Done right, it creates recurring revenue, scalable infrastructure and a genuine competitive moat. Done wrong, it can cost you six figures and eighteen months of your life with nothing to show for it.

The difference almost always comes down to the questions you ask — and when you ask them. This guide walks you through exactly what to put to any SaaS development agency before you hand over a single penny.

Can You Show Me a Live Platform You Have Already Built?

This is the single most important filter. Any agency can show you Figma mockups, polished pitch decks or screenshots lifted from a freelancer marketplace. What you need to see is a functioning, publicly accessible SaaS product that real users are paying for.

At By Design UK, our proof of work is Tackly.co.uk — a live SaaS platform we built and currently serve across 25 industries in the UK. You can log in, explore the interface and speak to users. That is the standard you should hold every agency to.

If a company cannot point you to something live, treat that as a serious red flag regardless of how impressive their portfolio PDF looks.

What Does a Custom SaaS Build Actually Cost in the UK?

Transparency on pricing separates professional studios from the rest. Here is a realistic breakdown of what bespoke SaaS development costs in the UK market right now:

• MVP / early-stage platform: £18,000 – £35,000. Core authentication, a primary workflow, billing integration and a basic admin dashboard.
• Growth-stage platform: £35,000 – £75,000. Multi-tenancy, role-based permissions, API integrations, reporting modules and onboarding flows.
• Enterprise SaaS: £75,000 – £200,000+. Complex data architecture, white-labelling, SSO, compliance frameworks (ISO 27001, GDPR-by-design) and dedicated support.

At By Design UK, our SaaS development starts from £18,000. That entry point gets you a properly engineered foundation — not a templated workaround dressed up as custom software. If an agency quotes you £4,000 for a SaaS platform, they are either using no-code tools they have not disclosed or they will ask for more money at every sprint boundary.

Ask for a fixed-price proposal or a clearly scoped time-and-materials agreement. Ambiguity in the contract will cost you later.

Who Actually Owns the Code and Data Once the Project Is Delivered?

This question catches many business owners off guard. Some agencies retain intellectual property rights over the codebase and licence it back to you on a monthly basis — meaning the moment you stop paying, you lose access to your own product.

Before signing anything, confirm in writing:

• Full IP transfer to your company upon final payment
• Access to all source code repositories (GitHub, GitLab or equivalent)
• Ownership of all database schemas and hosted data
• What happens to your product if the agency ceases trading

A reputable UK SaaS development company will have no hesitation putting all of this in the contract. If there is resistance or vague language like “shared ownership,” walk away.

What Does the Post-Launch Support and Maintenance Agreement Look Like?

Your SaaS platform does not stop needing attention the day it goes live. Servers need patching, third-party APIs change, payment processors update their SDKs and your users will find edge cases your test suite missed. Ask specifically:

• Is there a retainer available, and what does it cost? (Typical UK dev retainers run from £800 – £3,500 per month depending on scope.)
• What is the SLA for critical bug fixes — 4 hours, 24 hours, 72 hours?
• Is infrastructure monitoring included or billed separately?
• Will the same developers who built the platform maintain it, or does it get handed to a junior support team?

Continuity matters enormously in SaaS. A developer who already understands your data architecture can resolve a critical issue in two hours. A new developer reading your codebase for the first time might take two days.

How Do You Handle Scalability and Security From Day One?

Many lower-cost agencies build for where your business is today, not where it needs to be in three years. Ask to see evidence of how they architect for scale:

• Do they use containerisation (Docker/Kubernetes) or are you locked into a single server?
• How is multi-tenancy handled — shared database with row-level security, or separate databases per tenant?
• What security standards do they follow during development? (OWASP Top 10 should be table stakes.)
• How is GDPR compliance built into the platform architecture, not bolted on afterwards?

For UK businesses especially, GDPR-by-design is not optional. A platform that collects user data without proper consent flows, data deletion mechanisms and audit logging is a regulatory liability before it earns its first paying subscriber.

Are There Any Other Digital Services That Could Complement My SaaS Platform?

If you are building a SaaS product, you will almost certainly need a marketing presence, a landing page or an e-commerce front end alongside it. Working with an agency that covers multiple disciplines means fewer handoff problems and a more coherent end result.

By Design UK builds both custom SaaS platforms and Shopify stores, with Shopify builds starting from £499. Whether you need a standalone SaaS product, a Shopify integration that connects your store to your platform, or a complete digital ecosystem, we can scope it as a single project.

If you are ready to discuss your requirements, get in touch via our contact page and we will respond within one working day.

What Does a Realistic Project Timeline Look Like?

Be suspicious of agencies that promise a fully featured SaaS platform in six weeks. Be equally suspicious of those who cannot give you any timeline at all. A well-run agency should be able to offer:

• A discovery phase of 1–2 weeks to define scope, user stories and technical architecture
• An MVP delivery window of 10–16 weeks for a properly engineered platform
• Defined sprint cycles with demonstrable progress at each stage
• A clear process for handling scope changes without derailing the timeline entirely

Rushing a SaaS build to meet an artificial deadline is how you end up with technical debt that costs twice as much to fix as it would have done to build correctly the first time.

Why Does the Agency’s Location Matter?

Offshoring development is a valid cost-reduction strategy in some contexts, but for a SaaS platform that will be the core of your business, there are real advantages to working with a UK-based team:

• GDPR and UK data protection law familiarity built in by default
• Overlapping working hours for real-time communication
• The ability to meet in person for workshops, demonstrations and contract signings
• A UK legal framework if disputes arise

By Design UK is based in Enfield, EN3 7LW, and operates across the UK. You can call us directly on 020 3951 4908 during business hours — no ticket system, no offshore call centre.

Ready to Ask Us These Questions Directly?

We welcome the scrutiny. If you are evaluating SaaS development companies and want straight answers on pricing, timelines, IP ownership and architecture, we are happy to have that conversation.

By Design UK builds custom SaaS platforms from £18,000 and Shopify stores from £499. Our live reference platform, Tackly.co.uk, serves 25 industries and is available for you to review right now.

Send us your project brief via our contact page and we will come back to you with a no-obligation discovery call, or call us directly on 020 3951 4908.

The right agency will not pressure you for a quick decision. They will give you the information you need to make a confident one.