How to write a case study: a step-by-step guide with a template

Last updated: October 20, 2026

A case study (or customer success story) is a short piece that tells where a customer stood before working with you, why they chose you and what changed in the end. For sales teams it's one of the most persuasive things you can have, because a prospect reads the experience of someone like them. This guide walks through the steps for your first one and gives you a template to fill in.

1. Pick the right customer

Not every happy customer makes a good story. Start with customers who:

Have used your product regularly for a while, long enough for results to show.
Look like the buyers you want to win: industry, company size and need.
Are open to talking with you and to having their name used.

Customers who gave you a high satisfaction score, thanked your support team or renewed their contract are usually good candidates.

2. Get permission up front

Before writing, tell your customer what you'd like to use and where: company name, logo, the person's name and title, numbers. Some companies don't want to be named; you can still publish with an anonymous description such as "a mid-sized logistics company". See the guide to asking for testimonials for how to word the request.

3. Talk to the customer

The raw material of the story is the customer's own words. A short call or a written interview is enough. Always cover four topics:

Before: how did they do the work, and what was hard about it?
Decision: why did they look for a solution, and why you?
Rollout: how did getting started go?
Result: what changed, and how do they know?

When an answer is vague, ask for something concrete: instead of "we save a lot of time", ask "roughly how many hours a week?" For a ready-made question list and a tool that builds your own, see the customer interview questions guide.

4. Fit the story into Situation – Goal – Solution – Result

Readers don't read a case study top to bottom, they skim. These four parts help them find what they're looking for:

Situation: who is the customer and what were they dealing with before you? Describe the problem in their words.
Goal: what did they want to achieve? If it was measurable, say how they measured it.
Solution: how did they use your product? Not a feature list, but the work the customer did.
Result: what changed? A number with its time period if there is one; otherwise a concrete example.

Put a two-sentence summary at the top and state the result in the headline. "Company X uses our product" gets skipped; "Company X cut proposal prep time in half" gets read.

5. Use numbers and quotes carefully

Only use numbers the customer said or showed you; don't add estimates.
Give every number its period and baseline: "in 3 months", "compared with the previous quarter".
Don't round up. Writing "about 20%" for 18% costs you trust.
No numbers is fine: a concrete before-and-after example persuades too.
Pick one or two strong quotes; you can shorten the customer's sentence, but don't change it.

6. Get approval and publish

Send the draft to your customer and ask them to approve the quotes and numbers in particular. Once approved, don't leave the story in one place:

Its own page on your website, plus a short card on related product pages.
A one-page PDF attached to sales proposals.
A one-paragraph summary in sales emails.
A quote graphic on social media.

To see the parts of a good story with examples, read the B2B case study examples guide.

Case study template

Copy and fill in

Headline: [Customer] [concrete result] with [your product]

Summary: [Customer] is a [size] company in [industry]. With [your product], they [result] in [period].

Situation: [Customer] used to handle [process] with [old method]. That meant [problem].

Goal: [Customer] wanted [the outcome they were after].

Solution: They started using [your product] in [when]. [How they used it].

Result: In [period], [number or concrete change].

Quote: "[The customer's own sentence]" — [Full name], [Title], [Company]

Making this faster

Steps 3 and 4 take the most time: scheduling the call, writing it up and shaping it into a structure. CaseMagnet AI does that part for you: your customer gets a link, the AI asks the questions and, if an answer stays vague, asks for a concrete example; a draft in this structure comes out of the answers. If your customer gave no numbers, it doesn't make any up. You and your customer approve before anything is published.