By Design UK builds and migrates Shopify Plus stores for growing UK retailers who need more capability than a freelancer can offer, without the slow timelines and opaque invoicing common to larger agencies. We sit deliberately between the two: a small, senior team using AI-accelerated development to deliver fixed-price Shopify Plus builds, custom apps, and checkout extensibility work, with full source code ownership handed to you on completion.
Our Shopify work sits alongside our wider SaaS development practice, so when a Shopify Plus store needs a custom backend, an internal tool, or a bespoke customer portal beyond what Shopify’s platform supports, we can architect and build that too, on the same fixed-price, UK-based model.
Every engagement starts with a scoped, fixed-price quote before any code is written, so you know the total cost and timeline upfront. Full details of what’s included at each tier are on our Shopify services page.
Shopify builds through By Design UK typically range from £499 to £18,999, depending on scope. A focused Shopify Functions build or a targeted app integration sits at the lower end, while a full Shopify Plus migration with custom checkout logic, multiple integrations, and a bespoke front end sits toward the top of that range. For businesses that outgrow what Shopify Plus can natively support, we also build fully custom SaaS platforms, priced from £18,000 up to £650,000+ for enterprise-grade systems, detailed further under SaaS development. There are no hidden day-rate surprises: the quoted price is the price you pay, agreed before work starts.
Freelancers can be fast and affordable, but availability is often unpredictable, code quality varies, and there’s little accountability if they move on to another project mid-build. Traditional agencies bring process and polish, but that often comes with lengthy discovery phases, opaque hourly billing that can balloon well past the original estimate, and layers of account management between you and the developer actually writing your code. By Design UK is structured to avoid both failure modes: a small, senior, UK-based team, fixed-price contracts agreed upfront, AI-accelerated delivery to keep timelines tight, and full ownership of your source code handed over at the end, with no lock-in and no ongoing licence fees to us.
Rather than relying on case study slides, we point prospective clients to Tackly.co.uk, a live multi-toolkit SaaS platform we designed, built, and continue to run ourselves. It demonstrates real production infrastructure, ongoing maintenance discipline, and the same engineering standards we apply to client Shopify Plus builds and custom software projects. If you’d like to see how we work before committing, reviewing Tackly is a good starting point, and our about page has more background on the team and how we operate as a company based in Enfield, UK.
Launch is the beginning, not the end. Stores need monitoring, security patching, app updates, and incremental feature work as the business grows. Our Shopify support plans start from £299/month and cover proactive maintenance, priority bug fixes, and a bank of development hours for ongoing improvements. For clients running custom SaaS platforms alongside their storefront, equivalent support starts from £797/month. Full plan details are outlined on our support plans page, and if you’re unsure which tier fits your store, our team can recommend one during a scoping call.
Most Shopify Plus builds take between four and twelve weeks depending on scope, from a focused custom app through to a full platform migration with multiple integrations. AI-accelerated development helps us compress timelines without cutting corners on testing.
Yes. Full source code ownership transfers to you on project completion, with no ongoing licence fees or vendor lock-in. This applies to custom apps, theme code, and any bespoke SaaS components we build alongside your store.
Yes, platform migrations are one of our core services. We handle data migration, redirect mapping, theme rebuilds, and integration re-connection, all quoted at a fixed price before work begins.
It’s a common reason clients come to us. We provide the reliability and accountability of a UK-based, fixed-price agency without the slow overheads, backed by a live production platform, Tackly.co.uk, as evidence of our technical standards.