How to choose a Shopify agency: what it costs and what to check

Choosing a Shopify agency comes down to three questions: what you actually need built, what it should cost, and whether the team in front of you has done it before. A Shopify build covers the store setup, the theme, any custom features, the apps and integrations that connect it to the rest of your business, and migrations from other platforms. The good partners also think about where the customers are going to come from, because a beautiful store nobody visits is an expensive hobby.

This guide covers what the work includes, what Shopify development costs in the UK, six checks to run on any shortlist, how to move platforms without losing your rankings, and how to make product pages pull their weight. If you’d like to see how we work, our Shopify agency page sets out the process. The checks below apply to anyone you’re talking to, us included.

TL;DR

• A Shopify build covers setup, theme and custom development, integrations, migrations and ongoing support. The better partners also cover SEO and paid media, or at least plan the build around them.
• Shopify’s own fees start at £19 a month on the Basic plan billed yearly. Agency builds are a much bigger number: Shopify’s guide quotes $5,000 to $10,000 for a basic agency build and $15,000 to $35,000 for mid-tier custom work.
• Choose on evidence: similar live stores, one accountable team, a written scope and reporting tied to orders and revenue rather than traffic.
• Migrations are where rankings get lost. Map every old URL to a new one with permanent redirects, and keep them for at least a year.
• Product pages are where search, speed and conversion meet. Give them development time, not leftovers.

Table of Contents

• What’s included in a Shopify build
• Which parts of a Shopify build you need
• What Shopify development costs in the UK
• How to choose a Shopify agency: six checks
• How to move to Shopify without losing your rankings
• How to optimise Shopify product pages
• How to measure whether your Shopify build is working
• Common mistakes when hiring Shopify developers
• Our perspective
• Want a second opinion on your plans?
• FAQ
• Sources

What’s included in a Shopify build

The job has two halves: the technical store and the growth that’s meant to come through it. Shopify’s UK guide describes an ecommerce agency as one that helps brands sell more online by building and maintaining the technical infrastructure behind a store, running marketing and paid media, or both. A Shopify build partner lives mostly in the first half. The strongest keep an eye on the second, because a fast, well-built store with no visitors doesn’t pay for itself.

In practice, expect an agency to:

• Scope your requirements: catalogue size, integrations, markets and budget.
• Design the shopping experience, from navigation and collection pages down to the product page and basket.
• Build or customise the theme, plus any features Shopify doesn’t offer out of the box.
• Connect the store to the systems that run the business, such as stock, accounting, email and shipping.
• Launch, monitor and keep improving after go-live.

Agencies describe themselves in different ways: store developers, Shopify Plus partners, ecommerce studios. The labels change. The question that matters doesn’t: who is accountable when the store breaks, slows down or stops converting?

Which parts of a Shopify build you need

Not every business needs all of these. Match the list to where you are now.

Store setup and design

For a first store, this means configuring products, collections, payments, shipping rules and tax, then applying a theme that fits your brand. UK stores should have sterling pricing, VAT and UK delivery options set up from day one. Retrofitting them a week before launch is how launch dates slip.

Custom theme and feature development

This is where an agency earns its fee. Custom work might be a bespoke product page layout, a bundle builder, a subscription flow, a product configurator or trade pricing for B2B buyers. The point is to remove friction your customers actually feel, rather than bolting on a dozen apps that each add their own scripts.

Migrations and replatforming

Moving from WooCommerce, Magento or a bespoke platform involves more than copying products across. Customer accounts, order history, URLs and redirects all need a plan. We cover the redirect side in detail further down, because it’s the part most likely to cost you traffic.

Integrations and apps

Integrations connect Shopify to your ERP, warehouse, CRM, reviews platform and marketing tools. A good developer will tell you which apps to install, which features to build and which apps to avoid. Shopify’s developer documentation is frank on this: scripts from installed apps run on the browser’s main thread and compete with rendering and input, and it recommends removing any script that isn’t earning its performance cost.

Ongoing support and optimisation

A store is never finished. Retainers usually cover fixes, platform and app updates, small features, conversion testing and performance monitoring. If you sell seasonally, book the development capacity for peak trading in September, not in the week before Black Friday.

Marketing and visibility

Building the store is one job. Filling it with the right shoppers is another. Plenty of businesses now want the same partner to handle ecommerce marketing, including SEO, paid search and paid social, so the build and the acquisition plan pull in the same direction. If you’re still weighing up the commercial case for organic search, it’s worth understanding what SEO is worth to a small business before you set a budget.

What Shopify development costs in the UK

There are two separate bills: what you pay Shopify, and what you pay the agency.

Shopify’s own fees

Shopify’s UK pricing page lists these plans in November 2026, with prices per month:

• Basic: £19 billed yearly (£25 monthly), standard online card rate 2% + 25p.
• Grow: £49 billed yearly (£65 monthly), online card rate 1.7% + 25p.
• Advanced: £259 billed yearly (£344 monthly), online card rate 1.5% + 25p.
• Plus: from £1,800 a month, online card rate 1.3% + 25p.

Agencies love to push clients up a plan. Here’s a quick way to check whether it’s worth it, using an illustrative store taking £40,000 a month online. Moving from Grow to Advanced (billed yearly) costs an extra £210 a month and saves 0.2 percentage points on card fees, which is £80 a month at that turnover. It doesn’t pay for itself on fees alone until the store is putting roughly £105,000 a month through the checkout. Advanced may still be worth it for its other features, but it should be a reasoned decision, not a default.

What agencies charge for a build

Build quotes vary enormously because scope does. Shopify’s agency guide, citing Storetasker’s 2025 figures, puts basic agency builds at $5,000 to $10,000 and mid-tier custom builds at $15,000 to $35,000, with enterprise or Shopify Plus work running past $50,000. Those are US dollar figures from a US-led survey, so treat them as a rough guide to the shape of the market rather than a UK price list.

What moves a quote up or down:

• How many custom templates and features you need, versus adapting a theme.
• Catalogue size, variants and how messy the product data is.
• The number of integrations, and whether they have ready-made connectors.
• Whether you’re migrating from another platform and how many URLs need redirecting.
• How much content (product copy, collection copy, imagery) the agency has to produce.

Ongoing support and marketing are normally priced separately from the build, so ask for both in writing.

How to choose a Shopify agency: six checks

Use the six criteria below as a scorecard. The weighting depends on your business, but each one separates a dependable partner from an expensive surprise.

Relevant experience

• Look for: live stores in your sector, at your size and on your sales model, whether that’s D2C, B2B or subscription.
• Ask: “Which similar UK stores have you built, and what changed after launch?”

Team structure

• Look for: one accountable team rather than work passed between freelancers and subcontractors.
• Ask: “Who will I speak to each week, and are they in-house?”

Scope and process

• Look for: a written scope with milestones, a testing phase and a proper handover.
• Ask: “What’s included, what’s extra, and how are changes priced?”

Search and performance awareness

• Look for: a plan for page speed, structured data, clean URLs and redirects, written into the scope.
• Ask: “How will you protect our organic traffic during the build?”

Reporting

• Look for: reports tied to orders, revenue and enquiries, not just sessions and rankings.
• Ask: “What will I see each month, and what happens when results fall short?”

Support after launch

• Look for: defined response times and a support plan that starts on go-live day.
• Ask: “If checkout breaks at 8pm on a Friday, who fixes it?”

On reporting, Shopify’s own guidance sets a useful bar. It says good reporting shows issues as well as wins, and suggests asking agencies to show you campaigns or channels that underdelivered and what they changed as a result. An agency that only ever shows you the good months is telling you something.

Two practical tips. Ask to see live stores rather than portfolio screenshots, and test them on a mid-range phone on 4G. And insist on a fixed scope with a clear change process. Vague scopes produce vague invoices.

Watch out for the build-only trap

An agency that delivers a lovely theme and then disappears leaves you to work out acquisition on your own. Our view, set out in why traffic alone no longer converts, is that development and marketing should be planned together. Pages built with search intent and conversion in mind do better once the traffic turns up.

How to move to Shopify without losing your rankings

Map every URL that matters, redirect it permanently to its closest new equivalent, and keep the redirects in place for at least a year. That’s the short version. The long version is where most migrations go wrong.

Shopify uses fixed URL paths. Products live under /products/ and collections under /collections/, and Shopify’s help centre confirms you can’t redirect URLs that use those fixed paths. Coming from WooCommerce or Magento, almost every product and category URL will change, so the redirect map is a big job, not an afterthought. The same page notes that redirects only work from URLs that are actually broken, that standard stores can hold up to 100,000 redirects, and that redirects can be bulk-imported from a CSV.

Google’s guidance on site moves is clear about the rest. It recommends permanent redirects such as 301s, says they don’t cause a loss in PageRank, and advises keeping them “generally at least 1 year”. It also warns that rankings can fluctuate while Google recrawls the site, and that a small to medium-sized site can take a few weeks for most pages to move.

A sensible migration checklist:

1. Crawl the old site and export every URL that has traffic, links or rankings.
2. Map each one to the closest new page, product to product and category to collection. Avoid sending everything to the homepage.
3. Import the redirects before launch and test a sample on the new domain.
4. Carry over titles, meta descriptions and product copy that already ranks.
5. Submit the new sitemap in Search Console and watch for spikes in 404s for the first month.

If a migration is on your roadmap, bring your SEO team in before the designs are signed off. Our guide to technical SEO services covers what that work should include.

How to optimise Shopify product pages

Product pages are where the build, the content and the marketing meet. Shopify’s ecommerce SEO guide lists 11 ways to improve product pages, covering title tags, descriptions, page speed, reviews, FAQs and Google Merchant Center among others. Here’s how we’d prioritise them.

1. Get the foundations right

• Title tag and meta description: lead with the product name and the words a shopper would type, then add a differentiator such as material, size or UK delivery.
• One clear H1: the product name, not a slogan.
• Collections that make sense: a logical structure, so shoppers and crawlers can see how products relate.

2. Write descriptions for people first

Answer the questions a buyer has before they buy: what it is, who it’s for, what’s in the box, how it compares with the alternatives, the dimensions or the ingredients. Don’t paste the manufacturer’s description word for word. If 40 other retailers use the same text, Google has no reason to prefer your page.

3. Treat speed as a conversion tool

Shopify’s product page guide recommends you compress product images, cut unnecessary code and consider a content delivery network. Google’s Core Web Vitals give you the targets: the main content should load within 2.5 seconds, the page should respond to a tap in under 200 milliseconds, and layout shift should stay below 0.1. Audit your apps every quarter. An app you stopped using in March can still be loading scripts on every product page.

4. Add structured data

Product markup tells Google the price, availability, shipping and returns details for each product. Google’s documentation explains that pages where people can buy are eligible for merchant listing experiences, and recommends adding as many properties as you can. Most Shopify themes output some product markup by default. Your developer should check it’s valid and stays accurate when prices or stock change.

5. Use reviews, FAQs and trust signals

Reviews and a short product FAQ answer objections on the page and give search engines and AI assistants clear, quotable content. Put delivery times, returns terms and payment options near the buy button, so nobody has to open a second tab to find them.

6. Make buying easy on mobile

Baymard Institute’s running average of 50 studies puts online basket abandonment at 70.22%, and 17% of the US shoppers it surveyed said they’d abandoned an order because checkout was too long or complicated. Shopify’s checkout is largely standardised, so in our experience the friction usually sits earlier: fiddly variant selectors, an add-to-basket button that disappears below the fold, or a pop-up that covers half the screen. Test the whole journey on a phone, from landing page to payment.

7. Connect your product feed

Shopify’s guide calls integrating with Google Merchant Center essential, noting it’s required to appear in the “Popular Products” modules that show up in Google Search. An accurate feed also powers Shopping campaigns, which is where SEO and paid ads working together can lift your overall return.

How to measure whether your Shopify build is working

Agree the goals before anyone writes a line of code. Shopify’s agency guide suggests writing targets into the contract and evaluating performance at the 30-, 60- and 90-day marks, with reports that clearly show revenue attribution, return on ad spend and conversion rate trends. Monthly reporting is standard, and it suggests weekly check-ins where ad budgets are significant.

A simple framework:

1. Baseline (before launch): record conversion rate, average order value, organic sessions, Core Web Vitals and revenue by channel.
2. First 30 days: check tracking, indexing and redirects. Fix anything broken. Don’t judge sales yet.
3. 60 days: look at conversion rate by device and by top landing page, and which product pages are earning impressions in Search Console.
4. 90 days: compare revenue, ROAS and organic growth with the baseline, then agree the next round of tests.

Organic gains build more slowly than paid results, so judge SEO on the trend rather than one month. And ask for a report that links activity to orders. A spreadsheet of rankings isn’t a business result.

Common mistakes when hiring Shopify developers

• Choosing on price alone. A low quote with an open scope often ends up the most expensive once change requests start.
• Forgetting the content. Product descriptions, collection copy and FAQs have to be written by someone, and they affect search performance.
• Leaving speed until launch week. It’s far easier to keep a store fast from the start than to rescue a slow one.
• No redirect plan on a migration. Every old URL that matters needs a destination.
• Unverified tracking. If analytics and conversion events aren’t tested before launch, you can’t measure anything that follows.
• Assuming Google is the only shop window. Shoppers also ask ChatGPT and Gemini for recommendations, and clear, structured product data helps there too.

Our perspective

Most of the Shopify stores we’re asked to look at share the same story. The store was built well enough and launched on time, then sat waiting for customers who didn’t turn up in the numbers anyone hoped for. The build and the growth plan were treated as two separate projects, often by two separate suppliers who never spoke to each other.

We do it the other way round. Our Shopify development work sits in the same in-house team as SEO, Google Ads, Meta Ads and ecommerce marketing. The person deciding how a collection page is structured works from the same keyword and conversion data as the person running your campaigns. That sounds obvious. In our experience it’s surprisingly rare.

It also changes how we think about search. Shoppers increasingly discover products through AI assistants as well as Google, so we build stores with clean product data, useful content and structured information that serves both. And we report on orders, revenue and enquiries, because that’s what you’re paying for. You can see what that looks like in our Shopify project work.

One honest note. Not every store needs an agency. If you’re launching a small catalogue on a standard theme, a good freelancer and a free afternoon with Shopify’s setup guides may be all you need. Agencies earn their keep when the store has to integrate with other systems, migrate from another platform, or grow through paid and organic channels at the same time.

Want a second opinion on your plans?

If you’ve got quotes in front of you and want someone to sanity-check the scope, plan choice or migration plan, we’re happy to take a look. We don’t publish a rate card, because every store is different.

FAQ

How much does Shopify development cost in the UK?

It depends on scope. Shopify’s own agency guide, citing Storetasker’s 2025 figures, puts basic agency builds at $5,000 to $10,000 and mid-tier custom builds at $15,000 to $35,000, with Plus and enterprise work above $50,000. On top of that you’ll pay Shopify’s plan fee, which starts at £19 a month on Basic billed yearly, plus card fees and any paid apps.

Do I need a Shopify agency or can I use a freelancer?

For a simple store on a standard theme, a freelancer may be enough. When you need design, development, SEO and paid media working together, or cover for holidays and peak trading, a team gives you continuity and one point of accountability.

How long does a Shopify build take?

It depends on catalogue size, custom features, integrations and how quickly content and approvals come back. Ask any agency for a milestone plan with dates for design, build, testing and launch, and a list of what they need from you at each stage. If you’re migrating, allow time for redirect mapping and testing before launch.

Will I lose my Google rankings if I move to Shopify?

You shouldn’t lose them permanently if the migration is handled properly. Google says permanent redirects don’t cause a loss in PageRank, but rankings can wobble for a few weeks while it recrawls the site. The risk comes from missing or lazy redirects, especially sending old product URLs to the homepage.

Should SEO be part of a Shopify build?

Yes, and it’s best done during the build, when the structure, URLs, speed and structured data can be set up properly. Ongoing SEO then builds on that foundation with content, technical fixes and links. At Castle, SEO, generative engine optimisation and development sit in the same in-house team.

Which Shopify plan should I be on?

Start with the plan your features require, then check the card-fee maths. As an illustrative example, moving from Grow to Advanced only pays for itself on card fees once you’re processing roughly £105,000 a month online. Below that, upgrade for the features, not the fees.

Sources

• Shopify UK: Best Ecommerce Agencies Compared (2026)
• Shopify UK: Pricing
• Shopify: Ecommerce Product Page SEO: How to Improve It
• Shopify Help Centre: URL redirects
• Shopify.dev: Theme performance best practices
• Google Search Central: Site moves with URL changes
• Google Search Central: Core Web Vitals
• Google Search Central: Product structured data
• Baymard Institute: Cart abandonment rate statistics

Recommended

• Technical SEO Services: What They Include and How to Choose
• Ecommerce marketing in 2026: why traffic alone no longer converts
• How to choose a digital marketing agency in the UK