Ecommerce Agency UK: 10 Development Agencies Compared (2026)

A good ecommerce agency in the UK can show you live stores like yours, tells you who writes the code, and puts the build and support prices in writing before work starts. Below are ten UK ecommerce development agencies, grouped by the kind of buyer each one suits, followed by published UK prices and the questions to ask.

Ecommerce agency UK: 10 development agencies compared

We read each firm’s own pages on 11 October 2026 and wrote down what it says it does, where it is based and which platforms it builds on. We did not review their work or speak to their clients. Nine are outside firms. The tenth is FactoryJet, and we have marked it so you can read that entry with that in mind.

1. Charle

   Established in 2018. Its Shopify Plus page says it has launched 150+ Shopify sites. It builds new stores, migrates from Magento and WooCommerce, and runs SEO and email marketing on monthly plans. Its enquiry form offers budget bands from under £1,000 to £100,000+.

   Best for: Consumer brands that want design, search and email from one London team.

   Source: www.charle.co.uk/shopify-plus-agency/

2. Cake Agency

   Founded by the former owner of the shoe retailer Cloggs. It says it has built more than 200 ecommerce stores, that its 25+ staff all sit in one office, and that every store gets a 90-day warranty after go-live.

   Best for: Fashion and lifestyle retailers that want the store, an app and the marketing from one office.

   Source: www.cake.agency/shopify-agency

3. Swanky

   Founded in 2010 and Shopify-only since 2012. Its service menu covers migrations, subscriptions, selling abroad, B2B on Shopify and integrations. Case studies include a B2B migration for Natural Instinct and a migration with ERP integration for Fishpools.

   Best for: Brands moving to Shopify Plus that sell in more than one country or run subscriptions.

   Source: swankyagency.com/about/

4. blubolt

   Says it has delivered over 400 projects since 2006. It prints its timelines: an Express Launch typically takes 2 to 3 months, a Quick Launch 3 to 6 months and a Custom Build 6 to 9 months.

   Best for: UK consumer brands near £5M a year that want a migration with a published timeline.

   Source: blubolt.com/shopify-plus/

5. Kubix

   Builds and migrates stores, then runs paid media and conversion work on a retainer. Its site describes moving The Fine Cheese Co. from Magento to Shopify Plus while protecting search rankings, and four trade and consumer sites for Shires Equestrian. It says it uses no freelancers.

   Best for: Retailers with physical shops, and brands that want the migration and the marketing from one team.

   Source: kubixmedia.co.uk/

6. Velstar

   Says it has 21+ years of ecommerce heritage and has bought four specialist firms in three years. It builds Shopify Plus stores, headless storefronts and links to ERP, CRM and fulfilment systems. Its home page says the Euro Car Parts project handles over 12,000 online orders a day.

   Best for: Mid-market firms that sell to trade buyers as well as consumers.

   Source: velstar.agency/about

7. magic42

   Grew out of Mobile Fun, an online retailer founded in Birmingham in 2000, and still builds on Magento as well as Shopify Plus. It describes moving Alan Paine from Magento to Shopify Plus across several sites with an ERP integration.

   Best for: Merchants weighing Magento against Shopify Plus, and B2B sellers with an ERP.

   Source: www.magic42.co.uk/shopify-development-agency/shopify-plus-development/

8. Imaginaire

   Plans each store around search from the first wireframe, including how it shows up in AI answers. It prints a starting price, which is rare: Shopify and Shopify Plus builds typically start from £30,000, and it has completed projects up to £250,000.

   Best for: Brands whose sales depend on being found in search.

   Source: www.imaginaire.co.uk/

9. Underwaterpistol

   Says it built the 90th Shopify store in the world in 2006 and has been a Shopify Plus agency since 2014. Work is in-house and runs from design and development to migration, conversion work, SEO and subscriptions. It now lists AI consultancy.

   Best for: Brands already on Shopify Plus that want higher conversion and more repeat orders.

   Source: www.underwaterpistol.com/shopify-plus-agency

10. FactoryJet (that is us)

    A registered Shopify Partner that builds, migrates and supports stores, with a focus on the engineering below the theme: B2B set-up, checkout rules and the links to accounting and ERP systems. We also build AI agents that work inside the store. We show working software on your own data before a contract, and you own what we build.

    Best for: Brands and B2B sellers that want the store, the integrations and AI in one team.

    Source: factoryjet.com/uk/ecommerce-development

The labels overlap, so read past them. An ecommerce website design agency leads with how the store looks. Ecommerce website designers and developers build it, which is what ecommerce website development and ecommerce web development both mean. An ecommerce marketing agency or ecommerce digital agency runs the traffic afterwards: SEO, email and paid ads. Charle, Cake Agency and Kubix sell that marketing alongside the build, and Imaginaire plans every build around search, so it overlaps with an ecommerce SEO agency. For ecommerce web development in the UK, ask each firm which of those jobs it does in-house and which it hands to someone else.

Want a deeper cut on one platform? Our guide to the best Shopify Plus agencies for UK brands profiles 15 firms with their Shopify directory tiers. If you are not yet sure what the store needs, start with an ecommerce consultancy audit before you brief any agency.

Do you need a Shopify Plus agency?

Only if you will use what Plus adds. Shopify’s UK pricing page, read on 11 October 2026, listed Shopify Plus from £1,800 a month on a three-year term or £1,950 on a one-year term. Standard Shopify plans were £19 to £259 a month on yearly billing. That gap has to be earned by features you would otherwise pay for in apps or custom code.

• Native B2B on the same store. Company accounts, customer-specific price lists, payment terms and quick order, without a second wholesale site.
• Checkout rules. Checkout extensions and Shopify Functions let a developer change discounts, delivery options and payment methods by customer or basket.
• Selling abroad. Shopify’s UK page says the main store and nine expansion stores are included in the Plus fee, for one brand.
• Volume. blubolt says Plus typically becomes the most cost-effective option once a brand passes £1M in annual revenue, and Cake Agency says it belongs on the shortlist above £1 million.

Most of the firms above build on Plus. Swanky, blubolt and Kubix lead with migrations to it, and Velstar and magic42 with B2B. FactoryJet builds and migrates Shopify Plus stores for UK brands, including the links to Xero, Odoo, NetSuite and SAP Business One. The true cost of Shopify Plus guide lists the line items outside the plan fee.

What else ranks for "ecommerce agency uk", and how this guide differs

These are the business sites on Google’s first page for "ecommerce agency uk" in the United Kingdom when we checked on 24 September 2026 (DataForSEO), with the title Google showed for each. We list them so you can compare. The list leaves out directories and the whymatters.co.uk list, and we have not reviewed the services of firms not profiled above.

Most of these are agency home pages, and one is a top-12 list. When we opened junoecommerce.com on 11 October 2026 it redirected to the Tryzens site, so names on older lists move. This guide groups ten firms by the kind of buyer each suits, cites the page behind every claim, and puts published UK prices next to the shortlist.

What UK SMBs Actually Need from an E-Commerce Agency in 2026

UK SMBs need an e-commerce agency that delivers measurable performance. A pretty storefront on its own will not sell. The baseline expectation in 2026 is mobile-first design with Lighthouse Performance scores of 85 or higher and page load times under three seconds. Payment integration must cover what customers expect: card payments through Shopify Payments or Stripe, PayPal, Apple Pay, plus buy now, pay later options like Klarna and Clearpay. Your agency should handle PCI DSS compliance and implement 3D Secure 2 authentication to protect both your business and your customers from fraud without adding friction to legitimate transactions. Post-launch support separates professional agencies from build-and-disappear contractors. You need a partner who commits to security patches, plugin updates, uptime monitoring, and backups as standard practice, not vague promises to "fix things if they break." The checkout flow itself determines whether browsers become buyers. Guest checkout, progress indicators, address autocomplete, and abandoned cart recovery emails should be built in from day one. Every unnecessary form field or confusing step costs you orders. These are the minimum standard for competing in UK e-commerce in 2026. When evaluating agencies, ask for specific examples of Lighthouse scores, payment gateway set-ups, and support response times. Agencies that can't answer those questions aren't equipped to build a store that converts.

➡ Learn more: our UK ecommerce development service

Platform Decision Framework: WooCommerce vs Shopify vs Custom

Most SMBs choose their e-commerce platform backwards, picking a name they've heard instead of mapping their actual workflow. The right platform depends on three factors: catalogue complexity, team technical capacity, and whether you're selling B2C, B2B, or both. WooCommerce gives you complete control with no platform fee and no share of sales. You pay your payment provider: Stripe lists 1.5% plus 20p for standard UK cards. WooCommerce runs on WordPress, which makes it a strong choice for large catalogues that need buying guides and category landing pages. You'll need a developer for set-up and maintenance, but you own the entire codebase. Shopify handles hosting, security patches and PCI compliance for you, which matters for teams without technical staff. On Shopify’s UK pricing page in October 2026, card rates ran from 2% plus 25p on Basic to 1.5% plus 25p on Advanced, and stores that use another payment provider pay an extra 2%, 1% or 0.6% transaction fee depending on plan. For low-margin products, work those fees out per order before you choose. Custom platforms become necessary when B2B requirements exceed what off-the-shelf solutions handle. GPSUK, a promotional products distributor in Staines, needed request-for-quote workflows, artwork upload with print preview, multi-tier trade pricing, and Net 30/60/90 payment terms for distribution partners. FactoryJet built their B2B commerce platform on a custom B2B e-commerce stack that manages the customer pipeline, online quote negotiation and trade accounts in one system. The decision framework is straightforward: WooCommerce for content-heavy B2C with technical support available, Shopify for B2C without technical staff, Shopify Plus or a custom platform for B2B workflows where off-the-shelf limits cause daily friction.

➡ Learn more: Ecommerce Development

Market ranges as read on 11 October 2026 for our UK ecommerce website cost guide, which links each source. Platform fees from Shopify’s UK pricing page the same day. These are not FactoryJet prices.

UK E-Commerce Agency Pricing Models Decoded

UK e-commerce agency pricing tiers differ sharply in scope, and the hidden costs can exceed the quoted build fee if you don't clarify deliverables upfront. Designbox, updated August 2026, puts a small themed store at £2,000 to £6,000. That buys a template-based Shopify or WooCommerce set-up with basic payments and mobile-responsive design. It works for testing market fit or launching a single product line, but customisation is minimal. A custom store runs £6,000 to £20,000 on the same figures and adds custom design, advanced filtering and search, multi-currency support, SEO set-up, and conversion tracking through Google Analytics 4. This tier suits established businesses replacing an underperforming site. A large build runs £20,000 to £50,000 or more and handles complex requirements: ERP and CRM integration, trade accounts with tiered pricing, quote request workflows, and stock sync across warehouses. These builds justify the spend when manual processes cost more in staff time than the platform itself. Hidden costs surface when agencies quote the build separately from the essentials. Confirm upfront whether domain set-up, payment gateway set-up, content migration from your old site, product photography, and copywriting are included or billed separately. Hosting and maintenance often appear as recurring lines. Ask for a total-cost-of-ownership breakdown covering the first twelve months as well as the launch invoice, and ask whether VAT is included, because none of the UK guides we read says so.

Evaluating Technical Capabilities: Beyond Portfolio Screenshots

Ask any prospective e-commerce agency for Lighthouse Performance scores on their live client sites: actual production URLs, not mockups or staging environments. Anything below 85/100 signals slow load times that erode mobile conversions, and scores in the 60s or 70s mean you're losing customers before they see your products. Beyond the headline score, ask for Core Web Vitals: Largest Contentful Paint under 2.5 seconds, Cumulative Layout Shift under 0.1, and Interaction to Next Paint under 200ms. Those are Google’s own "good" thresholds, and they decide whether a mobile shopper finishes checkout or gives up. Google’s mobile-first indexing uses the mobile version of your site for ranking, so a desktop-first design works against you. Ask how the agency implements structured data, specifically Product schema, BreadcrumbList, and Organization markup, so product prices and stock can show in search results. If an agency dismisses schema as "technical SEO stuff," move on. Finally, request PageSpeed Insights reports for three recent client projects. Agencies confident in their technical work will share these immediately. Vague answers about "optimisation" without data mean you're buying a pretty storefront with a broken engine underneath.

Post-Launch Support: What to Get in Writing

A maintenance agreement keeps your store secure, fast and compliant, and the boundary between what it covers and what costs extra is where most disputes start. Get these in writing before you sign: how often platform, theme and plugin updates are applied; how backups are taken and how long they are kept; who monitors uptime and how fast they respond when checkout breaks; and whether performance checks and Core Web Vitals reports are included. What maintenance rarely covers: new features such as custom configurators, design overhauls, paid app or plugin licences, payment gateway changes, or platform moves. Those are usually billed by the hour or as a separate project. Published UK rates give you a yardstick: Open eCommerce says London developers typically charge £75 to £120 an hour and £50 to £90 outside London, and NB eCommerce and Design puts UK Shopify agency rates at £90 to £150 an hour. Ask whether changes are approved one request at a time, and whether there is a monthly minimum you pay whether you use it or not.

Red Flags: When to Walk Away from an E-Commerce Agency Proposal

If an agency won't commit to a week-by-week delivery plan with named milestones and client review gates, they're guessing, not building. Serious e-commerce partners map every stage: discovery, wireframes approved, a staging store live for you to test. Ask for three client references with full contact details: the director's name, a phone number, permission to ring them. Portfolio screenshots mean little; live URLs, Google PageSpeed scores, and a ten-minute conversation with the business owner tell you far more. If the agency hesitates or offers only first names and email addresses, ask why. No legitimate agency guarantees conversion rates or monthly revenue figures. They can improve checkout flow, site speed and product pages, but they cannot control your pricing, product-market fit, or the quality of traffic your ads deliver. Promises of "5% conversion guaranteed" or "double your sales in ninety days" ignore every variable outside their control. Technical specifications separate builders from decorators. A proper proposal states the hosting set-up, commits to a Lighthouse Performance target, defines backup frequency and retention, and lists security measures like firewall rules and PCI DSS checks. If the document focuses on colour palettes and stock photos but skips how the store runs, you're buying a brochure site with a payment button. Finally, walk away from urgency tactics. "Sign by Friday for twenty percent off" or "only two slots left this quarter" are car-dealership moves. Agencies confident in their work answer questions, provide contracts for legal review, and let you decide.

How FactoryJet Delivers E-Commerce on a Fixed, Up-Front Price

We are on the list above, so here is how we work, in plain terms. We hold client calls in UK working hours, write in British English, and have served 500+ businesses since FactoryJet was founded in 2014. Before a contract, we show working software on your own data: for a Shopify store, that means a draft theme built inside your own store. Every build is then quoted as a fixed price in writing after a short scoping call, based on catalogue size and integration complexity, and any support you choose is quoted the same way. Belle Maison, a lighting and home decor retailer, needed one store for trade buyers and retail customers, with payments and delivery zones; it went live in 6 days on Commerceflo, not Shopify. GPSUK, a Staines promotional products distributor, needed a B2B platform with RFQ workflows, trade accounts, artwork upload and print preview for custom merchandise, which we built on a custom B2B stack. A store with a custom theme takes 3 to 5 weeks, a store with subscriptions, B2B pricing or a migration takes 5 to 8 weeks, and a headless or custom build takes 8 to 14 weeks. The speed comes from standard stacks, reusable components, and a team that has built stores for retail, wholesale and hybrid models.

➡ Learn more: Ecommerce Development, Shopify Plus or an ecommerce consultant audit

UK agency ranges: Designbox, UK ecommerce website cost 2026 (updated 30 August 2026).

➡ Ready to launch your online store? Explore FactoryJet e-commerce development for UK businesses, or see our Shopify store builds.