How to write a customer case study

This guide is our view from writing and placing case studies on business websites; it quotes no outside source. The legal rules on using a customer's words (honest opinions, no distortion, typical results) are covered in our guide to reviews and testimonials on websites, and they apply to case studies too. This is not legal advice.

Permission and approval first

Ask before you write, not after. A case study names a business, describes its problems and often quotes a person, so the client has to agree to all of it. We suggest two steps, both in writing (an email reply is enough):

• Permission to feature them. Say what you want to publish (the client's name, logo, the contact's name, job title and photo, figures from the project) and where (your website, a PDF, social posts, sales emails). Some clients agree to the story but not the name; ask which they prefer.
• Approval of the final text. Send the finished draft, including every number and the quote, and publish only once they confirm. If they change the quote, use their version.

Keep both emails on file with the date. If the client later asks you to take the study down or remove their name, do it promptly. A named case study is also personal data; our website privacy basics guide covers the wider rules.

The best time to ask is right after a good result, when the client is pleased. Mentioning at the start of a project that you may ask for a case study later makes the request easier. A short customer feedback survey after each project shows which clients to ask.

A structure that works

Most good case studies follow the same five parts. Keep each one short; the whole study often fits in 400 to 800 words.

• Situation. Who the client is, in a sentence or two: the kind of business, its size and its market. A reader should be able to think "that sounds like us".
• Problem. What was wrong or missing, in the client's terms, and what it was costing them. "The old website could not be updated without a developer" is clearer than "digital transformation needs".
• What was done. The work, step by step, including the decisions and why you made them. Name the services involved and link to their pages. Mention a hurdle and how it was handled; a story with no difficulty reads like an advert.
• Result. What changed, measured where you can (see the next section) and described plainly where you cannot.
• Client quote. One or two sentences in the client's own words, with their name and role if they agreed. The best quotes come from a short call: ask what it was like before, what changed and what they would tell a peer, then pick a line and send it for approval.

Lead with the outcome in the title and the first line, for example "How a regional clinic cut its booking calls with online scheduling". The reader learns the point before deciding whether to read on.

Results: real numbers only

Numbers make a case study believable, but only real ones. Our rules:

• Use figures the client gave you or that you can show from their data (analytics, the booking system, sales records), and say what they measure and over what period: "form enquiries per month, three months before and after launch".
• Do not round up, pick the best week, or turn a small base into a big percentage without the raw numbers. "From 4 to 12 enquiries a month" is more honest than "200% growth".
• Say what else changed at the time (a new ad budget, a season, a price change) if it could explain part of the result.
• If there is no clean number, describe the result in words: faster replies, fewer phone calls about opening hours, staff who can now update the site themselves.

A single client's result is not a promise to the next one. Our testimonials section explains what that means when you publish a result, so we do not repeat it here. To turn results into money terms, see marketing ROI.

Formats: web page, PDF, short video

• Web page. The main version. It can be found in search, linked from service pages and shared with one URL. Give each case study its own page with a clear title, a photo of the real work or the client, and a link to the related service.
• PDF. Useful for sales: a one- or two-page version to attach to a proposal or hand over at a meeting. Make it from the web page, not the other way round, so the two say the same thing.
• Short video. A minute or two of the client talking about the project, filmed at their place of work. It is the most convincing format and the hardest to get, because it needs more of the client's time and their consent to be filmed. Add captions and a short written summary under it.

Start with the web page. Add the PDF when you send proposals, and the video when a client is happy to take part.

Where to place it

• On the matching service page. A short summary (the problem in one line, the result, the quote) with a link to the full study. This is where a reader is deciding whether you can do the job.
• Near the contact form. A quote or a one-line result next to the form answers the last doubt before someone gets in touch. Our website forms guide covers the form itself.
• On a case studies or work page. One page that lists them all, grouped by service or industry, linked from the menu. Link one or two from your About us page as well.
• In sales and email. Link the study in proposals and follow-ups, and in a newsletter when it is new.

A case study works best when it backs up a clear promise. Write your value proposition first, then pick case studies that prove it. In the marketing funnel, case studies serve the consider stage, when people compare you with others. If you are planning which pages your site needs, add them to your website content checklist.

A short template

Copy this outline and fill in each line:

• Title: How [client or kind of business] [achieved the result] with [the service].
• Summary (2 lines): [Client] needed [what]. We [did what], and [result with a real number and period].
• Situation: [Who they are, size, market, in 2 sentences.]
• Problem: [What was wrong and what it cost them, in their words.]
• What we did: [3 to 5 steps, one decision explained, one hurdle and how it was handled. Link the service page.]
• Result: [Measured change: what, before and after, over what period, and what else changed. Or a plain description.]
• Quote: "[Approved words]", [name], [role], [company].
• Next step: [A link to the service or the contact page.]

Before you publish, check: written permission and approval on file, every number traceable to a source, the quote exactly as approved, and a photo you have the right to use.

Frequently asked questions

How long should a customer case study be?

Long enough to cover the situation, the problem, what was done, the result and a quote. That is often 400 to 800 words on a web page and one or two pages as a PDF.

Can I publish a case study without naming the client?

Yes, if the client prefers. Describe them by industry and size, keep the facts accurate and still get their approval of the text. A named study carries more weight, so ask first.

What if the project had no measurable result?

Describe what changed in plain words, such as fewer calls, faster updates or a smoother booking process, and let the client's quote carry it. Never invent or estimate a figure to fill the gap.

What is the difference between a case study and a testimonial?

A testimonial is a short quote from a customer. A case study tells the whole story of one project and usually includes a testimonial as its quote.

Want help writing case studies and placing them on your service pages? See our services.