How to Brief an Ecommerce Agency Properly

We receive briefs every week. Some are excellent — clear, detailed, and focused on outcomes. They lead to accurate proposals, well-scoped projects, and satisfied clients. Others are vague wishlists that leave us guessing about what the brand actually needs, what they can afford, and what success looks like. Those briefs lead to misaligned expectations, scope creep, and frustration on both sides.

After twenty years of receiving, evaluating, and responding to ecommerce briefs — and after writing plenty of our own when we were on the brand side — we can say with certainty that the quality of the brief is the single strongest predictor of project success. Not the agency you choose. Not the budget. Not the platform. The brief.

This guide will show you how to write one that actually works.

Why the brief matters more than you think

A brief is not a formality. It is the foundational document that shapes every decision the agency makes — from who they assign to your project, to how they scope the work, to how they price it. A vague brief forces agencies to make assumptions. Those assumptions create gaps between what you expect and what they deliver.

Here is what a good brief does that a bad one does not:

• It attracts better proposals. Agencies invest more time and thought into responding to well-written briefs because they signal a serious, organised client who has done their homework.
• It produces accurate quotes. When agencies understand exactly what you need, they can scope the work properly. Vague briefs produce vague quotes, and vague quotes lead to budget overruns.
• It sets measurable success criteria. If the brief defines what success looks like, both parties can evaluate whether the project delivered. Without this, you are left arguing about subjective opinions.
• It reduces scope creep. A detailed brief creates a baseline that both parties reference throughout the project. When new requirements emerge, they can be evaluated against the original scope — and priced accordingly.
• It speeds up the process. Agencies that understand your requirements can start working faster. Ambiguity creates cycles of clarification that add weeks to timelines.

The time you invest in writing a thorough brief is returned multiple times over in project efficiency. Spending two days on the brief to save two weeks of miscommunication during the project is an excellent trade.

What to do before writing the brief

Before you write a single word, do these three things. They will make the brief significantly stronger.

Align your stakeholders

The most common source of project failure is not a bad agency or a bad brief — it is internal misalignment. If your marketing director wants a brand-led creative overhaul, your operations manager wants better integration with the warehouse system, and your CEO wants it done in four weeks for under £10,000, the project is doomed before it starts.

Before writing the brief, get all stakeholders in a room and agree on three things: the primary goal of the project, the budget range, and the decision-making process. Document these agreements. They form the foundation of the brief.

Audit your current state

You cannot explain where you want to go if you do not know where you are. Before writing the brief, gather data on your current performance: conversion rates, traffic sources, average order value, site speed scores, customer complaints, and known technical issues. If you are migrating platforms, document your current setup including apps, integrations, and custom functionality.

This data does two things. It gives the agency a baseline to work from, and it forces you to quantify the problems you are trying to solve. "Our site feels slow" is not actionable. "Our mobile PageSpeed score is 23 and our mobile conversion rate is 0.8%" is.

Research agencies first

Do not write a generic brief and send it to twenty agencies. Research first, shortlist three to five agencies that look like potential fits, and then write a brief that is specific enough to be useful. Each agency on your shortlist should have relevant experience in your sector, your platform, and your project type.

Read their case studies, visit their live portfolio sites, and check their content to understand how they think about ecommerce. This research also helps you write a better brief because you will understand what information agencies need. For guidance on the selection process, our guide on how to choose a Shopify agency covers the evaluation criteria in detail.

Anatomy of a strong ecommerce brief

A good ecommerce brief covers five areas: business context, current state, scope, budget and timeline, and process and people. Here is a detailed breakdown of each section.

Section 1: Business context and goals

This section tells the agency who you are and what you are trying to achieve. It is not a marketing brochure — it is a concise summary of the information the agency needs to understand your business and frame their proposal.

Company overview

Keep this brief. Two to three paragraphs covering what you sell, who you sell to, how long you have been trading, and your approximate revenue range. The agency does not need your full company history. They need enough context to understand your scale, market position, and customer base.

Project goals

This is the most important part of the entire brief. State your goals in specific, measurable terms. Good goals look like this:

• Increase mobile conversion rate from 1.2% to 2% within six months of launch.
• Migrate from WooCommerce to Shopify without losing organic search rankings.
• Reduce page load time to under 2.5 seconds on mobile.
• Launch in two new markets (Germany and France) with localised checkout experiences.
• Implement a subscription model for our core product range.

Bad goals look like this: "We want a modern, best-in-class website that reflects our brand values." That sentence contains zero actionable information. Every agency in the country will tell you they can deliver it.

Be honest about priorities. If you have five goals, rank them. The agency needs to know which are non-negotiable and which are aspirational. This ranking directly affects how they scope the work and allocate time.

Target audience

Describe your customers. Not in abstract persona terms, but in practical terms that affect the store build. Age range, device preferences, how they find you, what objections they have, what motivates them to buy. If you have customer survey data or analytics insights, include the relevant highlights.

For example: "Our core customer is a 35-50 year old woman purchasing gifts. 72% of our traffic is mobile. Most customers find us through Instagram or Google Shopping. The primary purchase barrier is uncertainty about sizing and materials." That paragraph gives an agency more useful information than a three-page persona document.

Section 2: Current state and pain points

Help the agency understand what you have today and what is not working.

Current platform and setup

Document your existing technology stack:

• Current platform (Shopify, WooCommerce, Magento, BigCommerce, etc.).
• Current theme or custom build.
• Apps, plugins, and integrations currently in use.
• Third-party systems the store connects to (ERP, warehouse management, accounting, CRM, email marketing platform).
• Payment providers and gateways.
• Any custom development or bespoke functionality.

If you are building a new store from scratch, state that clearly and list any systems the store needs to integrate with from day one.

Pain points

Be specific about what is not working. "The site is too slow" becomes "our mobile PageSpeed score is 23, and we believe this is caused by 14 apps, an unoptimised theme, and large uncompressed images." "We are not converting well" becomes "our desktop conversion rate is 2.1% but our mobile conversion rate is 0.8%, and we see a 65% cart abandonment rate."

The more specific you are about problems, the more precisely the agency can propose solutions. If you do not have this data, say so — a good agency will include an audit phase in their proposal to establish baselines before starting work. Understanding the real cost of performance issues helps frame the commercial impact of these pain points.

What you have tried

If you have already attempted to fix problems — whether internally, with a previous agency, or through app changes — share what you did and why it did not work. This prevents the new agency from proposing solutions you have already tried and failed with, and it gives them insight into the underlying complexity of the issues.

Section 3: Scope and requirements

This section defines what you want the agency to deliver. Be thorough, but focus on requirements rather than solutions. Tell the agency what you need to achieve, not how to achieve it. They are the experts in implementation; you are the expert in your business requirements.

Must-haves versus nice-to-haves

Separate your requirements into two clear categories. Must-haves are requirements that must be in the launch version. Nice-to-haves are features you would like but that can be delivered in a phase two or as part of ongoing development.

This distinction is critical for accurate scoping. If every requirement is listed as essential, the quote will be high and the timeline long. If you are clear about what can wait, the agency can propose a phased approach that gets you to market faster at a lower initial cost.

Functional requirements

List the specific functionality the store needs. For a Shopify development project, this might include:

• Product page requirements (size guides, colour swatches, bundling, reviews integration).
• Collection page filtering and sorting requirements.
• Cart and checkout customisation needs.
• Customer account features.
• Search functionality requirements.
• Multi-currency or multi-language support.
• Subscription functionality.
• Loyalty programme integration.
• Specific app requirements.

Design requirements

If you have existing brand guidelines, include them. If you have examples of stores you admire, share them — but explain specifically what you like about each example. "We like the clean product page layout on this store" is useful. "We like this store" is not.

Clarify whether you need the agency to handle web design or whether you have design assets ready. If you are providing designs, specify the format and level of detail. A Figma file with responsive breakpoints is very different from "our graphic designer will provide some concepts in PDF."

Content

Content is the single most common cause of project delays. Be explicit about who is responsible for content — product descriptions, photography, lifestyle imagery, blog posts, policy pages, and promotional copy. If you are providing content, state when it will be ready. If you expect the agency to create or source content, include that in the scope.

Many brands underestimate the volume of content needed for an ecommerce store. A store with 200 products needs 200 product descriptions, 200+ product photos, collection page copy, homepage content, about page copy, FAQ content, and more. This is weeks of work. Factor it into the timeline.

SEO requirements

If SEO is a priority, state it explicitly. Specify whether you need technical SEO setup, redirect mapping from an existing site, content strategy, or ongoing SEO support. If you are migrating from another platform, make it clear that preserving existing rankings is a priority — this significantly affects the migration approach and timeline.

Section 4: Budget and timeline

Budget

Include a budget range. This is the single most contentious piece of advice in this article, and it is also the most important. Brands resist sharing budget because they worry agencies will price to the maximum. But withholding budget information creates worse problems.

Without a budget range, agencies cannot determine whether to propose a bespoke build or a theme customisation. A £10,000 budget and a £50,000 budget produce fundamentally different solutions to the same brief. If you do not share budget, you will receive proposals ranging wildly in price and scope, making comparison impossible.

You do not need to state an exact figure. A range is sufficient. "Our budget for this project is £15,000-£25,000, including design and development" gives the agency the constraint they need to scope a realistic solution.

Timeline

State your target launch date and explain whether it is a hard deadline or a preference. A hard deadline changes how an agency approaches the project — they may need to increase the team size, which affects cost, or reduce scope to fit the timeline.

Be honest about what is driving the deadline. "We want to launch before Black Friday" is a legitimate commercial constraint. "Our CEO said three months" is a preference that may need adjusting based on scope.

Section 5: Process and people

Decision maker

Name the person who makes final decisions. This is not a bureaucratic formality — it is essential information. Projects stall when decisions need approval from someone not involved in the day-to-day process. If the founder needs to approve the homepage design, the agency needs to know that so they can plan the review cycle accordingly.

Day-to-day contact

Identify who will be the agency's primary contact. This person needs the authority to make day-to-day decisions, provide feedback promptly, and supply content and assets when needed. If this person cannot dedicate sufficient time to the project, state that upfront so the agency can adjust their communication approach.

Evaluation criteria

Tell agencies how you will evaluate their proposals. Price? Portfolio relevance? Technical approach? Cultural fit? Team composition? If they know how you are making the decision, they can structure their proposal to address your priorities. This also demonstrates that you have a structured evaluation process, which attracts more thoughtful proposals.

Submission format and deadline

Specify how you want to receive proposals, the deadline for submission, and the expected next steps. Will there be a presentation round? A chemistry meeting? A technical deep-dive? Lay out the process so agencies can plan their time and resources.

Common briefing mistakes

These are the mistakes we see most frequently, and they consistently lead to poor outcomes:

Writing an aspirational document instead of a requirements document. A brief is not a vision statement. "We want to be the best online shopping experience in our category" is not a requirement. "We need product page load times under 2 seconds, a three-step checkout, and size-guide overlays on all clothing products" is.

Listing features without explaining context. "We need a loyalty programme" leaves the agency guessing about complexity. "We need a points-based loyalty programme that integrates with Klaviyo, rewards purchases and referrals, and displays points balance in the customer account" gives them something to scope.

Sending the same brief to fifteen agencies. When agencies know they are competing against a large field, they invest less in each proposal. The proposals you receive will be templated and generic. Send to three to five pre-qualified agencies and tell them the size of the field. This encourages investment in the response.

Omitting constraints. If you have a firm launch date, a fixed budget, or technical constraints (specific integrations, regulatory requirements, accessibility standards), state them. Constraints are not weaknesses — they are parameters that help the agency design a realistic solution.

Focusing on design preferences instead of business outcomes. "We want a minimalist, modern design with lots of white space" is a design preference. "We need to increase our mobile conversion rate by 50% and reduce our bounce rate on product pages" is a business outcome. State the outcome and let the agency propose the design approach that achieves it. For practical guidance on what strong product page design looks like, our guide covers the principles.

Not including technical context. If your ERP system only supports CSV imports, or your warehouse uses a specific shipping integration, or you have regulatory requirements for product data — these constraints dramatically affect scope and cost. Omitting them leads to inaccurate quotes and nasty surprises mid-project.

What happens after you send the brief

Allow time for questions

Good agencies will have questions. This is a positive sign — it means they are reading the brief carefully and thinking about your project specifically. Allow a question period of three to five business days after sending the brief. Consider holding a single Q&A session that all shortlisted agencies can attend (separately) to ensure consistent information sharing.

Evaluate proposals methodically

Create a simple scoring matrix before you receive proposals. Score each proposal against your stated evaluation criteria. This prevents the common trap of being swayed by the best presentation rather than the best fit.

Pay attention to what agencies say about your brief. If they identify requirements you missed, flag potential risks, or push back on unrealistic timelines, they are demonstrating the kind of thinking you want from a partner. Agencies that simply agree with everything in the brief are either not reading it carefully or telling you what you want to hear.

Check references

Ask for references from clients with similar project types and budgets. A reference from a brand that spent £200,000 is not relevant if your budget is £15,000 — the experience, team, and process will be different. Ask references specific questions: Did the project deliver on time? On budget? Did the agency proactively identify issues? How is the ongoing relationship?

Trust the process

A good brief leads to a good selection process, which leads to a good project. The two days you spend writing a thorough brief will save weeks of wasted time during the project. It is the highest-leverage activity in the entire agency engagement process.

The briefs that lead to the best projects share one trait: they focus on outcomes, not outputs. They describe the business problem to solve, not the solution to build. That distinction gives the agency room to apply their expertise.

Andrew Simpson, Founder

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A brief checklist

Before you send your brief, check that it includes:

1. Company overview and market position.
2. Specific, measurable project goals ranked by priority.
3. Target audience description with device and behaviour data.
4. Current platform, apps, and integration details.
5. Specific pain points with data where available.
6. Must-have and nice-to-have requirements separated clearly.
7. Design requirements or references with explanations.
8. Content responsibility and readiness status.
9. Budget range.
10. Timeline with deadline rationale.
11. Decision maker and day-to-day contact named.
12. Evaluation criteria and selection process.
13. Submission deadline and format.

For related reading on working with agencies effectively, see our posts on how to choose a Shopify agency, questions to ask your Shopify agency, and agency versus freelancer. If you are considering ongoing support, our guide on what to expect from an ecommerce retainer covers the ongoing relationship structure.

If you are ready to start a project with us, get in touch. You do not need a polished brief to begin the conversation — we are happy to help you shape the requirements.