How to choose an e-commerce agency comes down to three checks: the agency must know the platform that fits your shop, show proof from live shops that sell, and offer terms that protect your data, your revenue during migration and your ability to grow. Choose on those, not on the number of logos in a pitch deck or the lowest day rate. This guide explains how to match platform to business, what proof to ask for, the questions that separate builders from sellers, the European points that matter at checkout and the contract terms to read before you sign.
Last updated: 22 October 2026.
Where should you start?
An online store is a business system, not a website with a cart. It touches stock, payments, tax, delivery, returns, customer service and marketing. Before you speak to an agency, write down the facts that shape the project: what you sell and how many products, where you sell and in which currencies and languages, how orders reach the warehouse, which systems must connect (accounting, ERP, stock, marketplaces), who will run the shop each day and your revenue goal for the next two years.
Be honest about what is not working today, too. Slow pages, abandoned carts, manual order handling or a back office the team avoids are all clues to what the new shop must fix, and they help an agency propose the right scope rather than a generic one.
With that page in hand, agencies can tell you whether they are a good fit, and you can compare their answers. Our article on running an online store in-house or outsourced helps decide which parts you keep and which you hand over.
At Odduel, a creative and technology agency in Barcelona and São Paulo, our e-commerce service starts from this page of facts. The platform is chosen from it, not before it.
In short: describe your shop first. Choose an agency that is strong on the platform that suits that shop. Ask for live shops and the work behind them, not screenshots. Check how they handle migration, checkout and European rules. Read the contract for ownership, accounts and support after launch.
Why is platform fit the first filter?
Agencies usually specialise. A team that builds excellent Shopify themes may be the wrong choice for a complex B2B catalogue with custom pricing, and the reverse is just as true. Use the platform that fits your shop to narrow the field.
| Platform | Fits best when | What to check in the agency |
|---|---|---|
| Shopify | Direct-to-consumer brands, fast launch, small team to run it | Custom theme work, app choices, Shopify Markets for several countries |
| WooCommerce | Content-led shops, existing WordPress site, full control of hosting | Performance, security updates, hosting plan, plugin discipline |
| Adobe Commerce (Magento) | Large catalogues, complex B2B rules, many integrations | Certified developers, hosting, upgrade path, long-term cost of ownership |
| Headless (any back end with a custom front end) | Unique experiences, content and commerce mixed, high performance needs | Front-end engineering, content management, who maintains two systems |
If you are deciding between two enterprise platforms, our comparison of Shopify Plus vs Adobe Commerce sets out the trade-offs in detail.
Which proof matters?
Every agency has a portfolio. What you need is proof that the work sells and lasts.
- Live shops you can buy from. Go through a purchase on a phone. Check speed, search, filters, product pages, cart, checkout and the order confirmation.
- Shops similar in complexity to yours. Catalogue size, number of countries and integrations matter more than sector.
- What the agency actually did. Design, build, integrations, migration, marketing, ongoing support: ask which parts were theirs.
- Client references. Ask to speak to one or two clients, ideally one whose shop has been live for more than a year.
- Before and after. A redesign or migration they ran, and what happened to search visibility and sales in the months after.
Which questions should you ask an e-commerce agency?
The answers tell you how the agency thinks. Listen for specifics and for questions back to you.
- “Which platform would you choose for us, and what would make you choose another?” A good answer depends on your catalogue, markets and team, not on the agency’s habit.
- “How would you migrate our products, customers, orders and addresses without losing search traffic?” Expect a redirect plan, data mapping and a test run.
- “Which third-party apps or plugins would you install, and why?” Fewer is usually better: each one adds cost, risk and weight.
- “How do you design and test the checkout?” Look for mobile-first testing, payment methods that suit your markets and clear error states.
- “What does support look like after launch?” Response times, who answers, how updates and security patches are handled.
- “Who owns the theme, the code and the accounts?” You should.
Which European points must agencies get right?
Selling online in the European Union adds rules that a good agency builds in without being asked. Use these as a check.
- Prices and VAT. Prices to consumers shown with VAT included, and the rules for distance sales across EU countries handled correctly with your accountant.
- Consumer information and withdrawal. Clear information before purchase and the right of withdrawal for most distance sales, as set out in the Consumer Rights Directive.
- Payments. Strong customer authentication for card payments and the local methods your customers expect in each market.
- Data protection and consent. Cookie consent before tracking, lawful marketing emails and a privacy notice that matches what the shop actually does.
- Accessibility. Since 28 June 2025 many online stores selling to consumers fall under the European Accessibility Act; checkout, forms and product pages must be usable with a keyboard and a screen reader.
An agency that raises these points itself, early, is one that has shipped shops in Europe before.
What are the red flags in e-commerce proposals?
Some signals should make you slow down.
- A long list of plugins or apps proposed before anyone has looked at your operations.
- No mention of migration, redirects or search visibility in a redesign.
- A checkout designed only on desktop.
- Theme, code or the store account held in the agency’s name.
- A price that covers launch only, with no word on hosting, updates or support.
What does working with a good e-commerce agency look like?
Knowing the shape of a well-run project helps you judge the proposals. Most good e-commerce projects follow this order.
- Discovery. Workshops on products, customers, operations and systems; a review of the current shop and its data; agreed priorities for the first release.
- Structure and user experience. Navigation, category structure, search and filters, product page content and the checkout flow, tested on phones first.
- Design. A shop design built as a system of templates and components, so new collections and campaigns can be launched without a developer.
- Build and integrations. The theme or front end, payments, delivery, tax, stock and accounting connections, with a staging shop you can test.
- Migration. Products, customers, orders and content moved and checked, with every old address redirected to its new one.
- Testing and launch. Real test orders on every payment method, on several devices, then a launch at a quiet time with the team on hand.
- After launch. Monitoring, fixes, speed and conversion improvements, and regular updates.
If a proposal skips steps, ask who does that work. Usually the answer is you.
How to choose an e-commerce agency: a short scorecard
Score each shortlisted agency from 1 to 5 on platform fit, live proof, migration plan, checkout quality, European compliance, support terms and ownership of code and accounts. Add the scores, then look at the weakest area of the agency you prefer: if it is where your shop carries the most risk, keep looking.
How do you compare proposals fairly?
Line the proposals up against your page of facts. Check that each covers the same scope: design, build, integrations, data migration, content entry, training, testing and support. Ask for anything missing to be priced separately so the totals compare like with like.
Look at how time is divided. A proposal that spends almost nothing on discovery, migration or testing is cheaper because it leaves those risks with you. Our list of e-commerce website features is a useful checklist for what should be in the first release.
Questions people ask
What does an e-commerce agency do?
An e-commerce agency plans, designs and builds online stores and connects them to the systems behind them: payments, stock, delivery, accounting and marketing tools. Many also migrate shops from one platform to another, run search and advertising, and support the shop after launch. Ask which of these each agency actually does itself and which it subcontracts.
Should I choose a Shopify agency or a general web agency?
If Shopify suits your shop, an agency with strong Shopify experience will usually move faster and avoid the platform’s common pitfalls. A general web agency can be right when your shop is part of a larger content site or needs a custom front end. Choose on proof with your platform, at your level of complexity.
How do I know an e-commerce agency is good?
Buy something from shops they built, on a phone, and judge the whole journey from search to confirmation. Speak to a client whose shop has been live for over a year. Ask how they handled a migration and what happened to search traffic. Good agencies answer specifically and are open about problems they solved.
What should be in an e-commerce agency contract?
The contract should assign the theme, code and designs to you on payment, keep the store, domain, payment and analytics accounts in your name, include a data processing agreement where personal data is handled, define acceptance criteria, a warranty period for fixes, response times for support and how updates and security patches are priced after launch.
How long does it take an agency to build an online store?
A shop on Shopify with a custom theme and a moderate catalogue often takes a couple of months; a complex B2B shop with integrations and migration can take much longer. The biggest variables are integrations with other systems, the quality of product data and how quickly decisions are made. Ask each agency for a phased plan.
Can an e-commerce agency also run our marketing?
Many can, and it helps when the people who built the shop also understand its data, its speed and its checkout. Check that marketing is a real practice in the agency, with its own specialists and reporting, rather than an add-on. Ask how they would measure results and how often you would review them together.
Write your page of facts, pick the platform that suits it and shortlist agencies with proof on that platform. If you would like us to look at your shop, our e-commerce service covers design, build, migration and support; tell us what you sell.
