Creating an e-commerce website isn't just about "putting products online." You're building a system that must sell, reassure customers, collect payments, deliver, manage returns, provide reliable data, and integrate seamlessly with your organization. When a project starts without a framework, the same problems almost always arise: quotes that are impossible to compare, delays, "forgotten" features, poor SEO, mediocre performance, and a store that's difficult to manage on a daily basis.
The specifications document is therefore not an administrative document. It's the best guarantee for the success of your e-commerce website creation, whether you're working alone, with a freelancer, or with an agency. In this guide, you will build a clear, concrete, and actionable specifications document, with a template and checklist at the end.
Why a specification document is the real first step
On an e-commerce site, what you see is rarely what's most expensive to fix. The design and pages are visible, but the real work lies hidden in what's managed from the back office: managing product variations, calculating shipping costs, taxes, multi-channel inventory, transactional emails, SEO redirects, tracking, and checkout. If these issues aren't addressed beforehand, they can become real problems later on.
A specifications document offers three immediate benefits. First, it transforms your intentions into decisions. Second, it makes your priorities explicit (what is essential for launch, what can wait). Finally, it allows you to obtain comparable quotes, because everyone responds based on the same criteria.
In other words: creating an e-commerce site isn't about choosing a platform or a service provider. It's about precisely defining what the site must accomplish, and how.
Business objectives: what the site should "sell" (and measure)
An e-commerce site sells products, but it also sells trust. Therefore, your specifications begin with your business objectives, not a list of features. A site built to develop customer acquisition is not the same as one built to maximize repeat purchases. A site focused on profit margin is not managed like one focused on volume.
Describe your main objective in simple terms: increase revenue, reduce reliance on marketplaces, improve profitability through direct sales, develop a customer base, launch a new product line, or expand into a new country. This sentence will serve as your compass for making the rest of your decisions.
Next, specify how you will measure success. The right level of tracking isn't about "measuring everything," it's about "measuring what guides your decisions." Average order value, conversion rate, checkout abandonment rate, return rate, and repeat customer percentage: these indicators are already very helpful. They prevent you from judging the site based on impressions.
Finally, be realistic about your internal constraints. Who manages the catalog? Who answers inquiries? Who prepares the orders? In creating an e-commerce website, the tool is never the real problem. The real problem is the organization that has to populate and operate it.
Catalog: products, variants, bundles, filters, search
The catalog is often the first source of friction because it's rarely considered as a structure. Yet, it's what determines your navigation, your filters, your SEO pages, your merchandising, and even your customer service.
In the specifications, describe your catalog as a system. How many actual SKUs? How many variations per product? Do you have customizable products? Options that change the price? Stock or preparation constraints? These elements dictate how to build product sheets and manage inventory.
Also specify your content standard for each product page. A high-performing e-commerce product page isn't just a description. It must explain the benefits, address objections, clarify usage, and demonstrate quality. If your positioning is premium, this generally implies more useful images, more evidence, greater clarity, and less clutter.
Next, formalize your bundling and recommendation strategy. Do you want to offer bundles, multipacks, complementary products, or deals that increase the average order value? This isn't a minor detail. It's often one of the best ways to optimize the profitability of an e-commerce site, provided it's integrated from the design stage.
Finally, use the customer's vocabulary for search and filters, not your internal jargon. A "material" or "format" filter is useful, but a "use" or "need" filter is often even more so. Effective search saves the visitor time and increases the store's revenue.
Customer journey: essential pages + mobile-first UX
The majority of e-commerce sessions take place on mobile devices, and most friction stems from a user journey that's "adapted" rather than thoughtfully designed. Mobile-first doesn't mean "smaller version." It means: clear text, simple thumb actions, a clear information hierarchy, and reassurance provided at the right time.
In your specifications, describe the customer journey before describing the pages. How does the customer discover your products? How do they compare them? What reassures them? When do they see the full price, delivery times, and shipping costs? At what point do they sign up, and why? This narrative highlights the steps in the decision-making process.
Some pages are obviously essential (homepage, categories, product pages, shopping cart, checkout, trust pages), but effectiveness lies in the flow. A product page, for example, should first entice, then clarify, then provide proof, and finally offer security. On mobile, this often translates to a clean structure, with readable sections and a well-placed call to action, without being intrusive.
If you want to further improve your sales performance once your site is live, keep this guide to improving conversion rates handy. It will help you prioritize the optimizations that have the greatest impact.
Payment, delivery, returns, taxes: rules and exceptions
This is the most "operational" part of the specifications, and paradoxically the easiest to write. Why? Because this is where the edge cases reside. And this is precisely what creates delays and additional costs if you discover them too late.
Regarding payment, describe the essentials for your market and target audience. Expectations vary from country to country. Also clarify the rules: installment payments, deferred payments, B2B with approval, or quote management. The goal is to ensure the purchasing process reflects your customers' realities.
Regarding delivery, go beyond simply saying "we deliver everywhere." Where are you starting from? Which zones? Which carriers? What are your realistic delivery times? How are shipping costs calculated? What happens if a cart contains a heavy item, a fragile item, or a pre-ordered item? A successful e-commerce site is often one where delivery is included, not left to the imagination.
Be clear about returns. Include details such as the timeframe, conditions, who pays, refund or store credit, and exchange policy. A clear return policy builds trust, and reassurance drives sales. Conversely, a vague policy costs customers in terms of support and conversions.
Finally, define the tax and geographical scope. France only, Europe, international. Even without going into legal details, this decision influences delivery, required information, VAT, and sometimes the payment experience.
SEO: site structure, collections/categories, content, redirects
An e-commerce website can be beautiful but invisible. SEO isn't an afterthought: it's a way to organize your online store to meet demand and allow search engines to understand your offering unambiguously.
In the specifications, start with the site map. Define your main categories and the logic of the subcategories. The key is clarity: each important page must address a single intent, from a unique angle, to prevent multiple pages from competing for the same search queries.
Next, define your content strategy. On an e-commerce site, useful content isn't just "a blog." It also includes category pages that guide customers, product pages that explain, guides that reassure them, and trust pages that clarify information. Your SEO depends primarily on your ability to publish useful content that is relevant to your customers' search queries.
If you're migrating or redesigning an existing site, the redirection plan is non-negotiable. It protects your traffic, your rankings, and your historical data. To understand this topic in detail, you can refer to "Shopify Redesign: Securing SEO and Conversion ," which explains the migration process and key considerations.
Tracking & data: GA4, pixels, consent, upcoming events
Without reliable data, you optimize by instinct. And in e-commerce, instinct is often misleading, because problems hide in the details: a shipping fee that arrives too late, a missing payment method, a product sheet that doesn't explain enough, a mobile phone that is too slow.
Your specifications must define what you want to measure for management purposes: product visibility, cart additions, payment start times, purchases, but also performance by channel and by product. The principle is simple: measure what helps you make decisions, not what gives you an "impressive" dashboard.
Plan for a clean installation of Google Analytics 4 and, if you're running ads, use appropriate pixels. Also, consider consent: it must be compliant, but it should remain understandable and not disrupt the user experience. An imperfect but consistent measurement is better than a "complex" one that no one understands.
Integrations & operations: ERP/PIM/WMS, marketplaces, email, customer support
An e-commerce website isn't a standalone project. It's integrated into your daily operations: inventory management, order preparation, invoicing, customer support, email marketing, and sometimes marketplaces and points of sale. The sooner you clarify these interactions, the more stable and easier to manage your site will be.
Start by identifying the source of truth for your inventory and catalog. If your inventory resides somewhere other than the online store, you need to define how and how frequently it synchronizes. Out-of-stock items displayed too late are a direct source of frustration and support tickets.
Next, describe your email and customer service needs. Transactional emails should be clear, reassuring, and consistent with your brand image. Customer support should offer a simple process: contact, order tracking, and returns. The goal isn't to pile on tools, but to build a seamless experience for both the customer and the support team.
If you also sell on marketplaces, specify your expectations: inventory synchronization, order management, price consistency, and returns handling. Even if you start with a simple setup, writing down your requirements will prevent you from having to rebuild later.
Performance & quality: speed, accessibility, QA, recipe
Performance is one of the most underestimated levers in creating an e-commerce website. A slow site lowers conversion rates, increases customer acquisition costs, and degrades the mobile experience. Quality, however, isn't just about "it works." It's proven through a structured approach.
In your specifications, define a clear objective: a fast, stable, and mobile-friendly website, even under average network conditions. This influences very concrete choices: image size, simplicity of animations, application selection, and technical discipline.
Next, plan a test run before launch. A useful test run will test key user journeys and edge cases: adding to cart, promo codes, shipping costs, taxes, emails, payment, returns, and mobile display. This testing period is often what separates a smooth launch from a painful one.
Also consider accessibility and readability. Contrast, text sizes, clear buttons, consistent navigation. This isn't a luxury; it's a way to reduce friction for everyone.
Planning & budget: how to estimate (MVP vs V2)
A realistic budget is built on a clear scope. Without specifications, you'll end up with either a vague or overly optimistic estimate. With specifications, you can estimate the project in stages.
The MVP isn't a "cut-rate" website. It's a site that perfectly covers the essential scenarios for selling cleanly: a clear catalog, a seamless mobile experience, reliable payment, transparent delivery, a solid SEO foundation, and actionable tracking. Version 2 comes next, powered by data: more advanced bundles, automations, enriched content, conversion optimizations, and additional integrations.
In the specifications, write down what is essential for the launch and what can wait. This simple separation protects your schedule, your budget, and your quality.
How to use this document to request 2–3 comparable quotes
A good set of specifications should allow several service providers to respond with the same level of understanding. When you request quotes, it's not just the price that should be comparable: it's the scope, the assumptions, the deliverables, and the methodology.
Send the document, then explicitly request a structured response: what's included, what's optional, what depends on prerequisites, and how the testing and launch are handled. This is also the point at which you can decide whether you want to choose an agency to create an online store or opt for another organization. The important thing is to obtain truly comparable proposals, rather than three different visions of the same project.
If you're going with Shopify
If your e-commerce website is being built on Shopify, the challenge is often to start with a clean, fast, and easy-to-maintain foundation, while still having room to grow. For a step-by-step method, you can follow the "Create a Shopify Store Yourself" tutorial , which details a structured approach, from initial planning to launch.
E-commerce specifications template
Finally, here's a simple template you can copy and paste. The idea isn't to produce a lengthy document, but a clear one that aligns your objectives, scope, and constraints.
1) Context and objectives. Explain your business, your target audience, your promise, and what your e-commerce website creation should primarily achieve.
2) Success indicators. Define the metrics that will guide your decisions after launch, without trying to measure everything.
3) Catalogue. Describe the product structure, variants, stock management, and the expected level of content on the product sheets.
4) Customer journey. Describe the ideal visitor journey, especially on mobile, and specify the points of reassurance.
5) Payment, delivery, returns, taxes. Write down the rules and exceptions that your store must handle unambiguously.
6) SEO. Define the site map, priority pages, content strategy and, if necessary, the redirection plan.
7) Tracking. Define what you want to track and how you will use this data for piloting.
8) Integrations. List the tools to be connected and clarify the source of truth for the stock and catalogue.
9) Quality and performance. Set a speed target and a recipe plan before launch.
10) Planning and versions. Clearly separate MVP and V2 to secure budget, deadlines and quality.
In conclusion, a successful e-commerce website is one that sells, is easy to manage, and can evolve without needing to be rebuilt. The specifications document is the framework that enables this success. If you create it correctly, you save time, avoid surprises, and maximize your chances of having a high-performing online store from the very first weeks.
