How to Write an ICP a Lead Source Can Actually Use
Ask most founders who their ideal customer is and you'll get something like "B2B companies that want to grow." That's true, and it's useless. Nobody — no person, no database, no automated system — can go and find "companies that want to grow." Every company wants to grow.
An ideal customer profile only works if someone else can take it and come back with a list. If they can't, it's a description of a feeling, not a profile. Here's how to write one that holds up.
The test: could a stranger build a list from it?
Before anything else, run this check. Hand your ICP to someone who has never heard of your business and ask them to find 20 matching companies and the right person at each one. If they have to come back and ask "what do you mean by that," the profile isn't finished.
Every line in a usable ICP is something that can be searched, filtered, or checked. "Innovative companies" fails. "Companies founded after 2018" passes. "Decision-makers" fails. "Head of Sales or VP of Sales" passes.
The five fields that actually matter
You don't need a 10-page persona document. You need five things, each specific enough to filter on.
1. Industry. Name the actual industries, not the category. "Tech" is too broad to mean anything. "B2B SaaS" is better. "B2B SaaS selling to finance teams" is better still.
2. Company size. Give a range in employees, not a word like "small" or "mid-market." Those words mean different things to different people — a 200-person company is small to an enterprise seller and huge to a freelancer. Write "10–50 employees."
3. Geography. List the countries you can actually sell into and serve. Include time zones and languages in that decision, not just where the market is biggest. If you can't take a call at 9am their time, think twice before listing them.
4. Job titles. Name the two or three titles of the person who actually says yes. Not everyone who might be interested — the person who signs. If you're not sure, look at who approved your last few deals.
5. Exclusions. This is the field most people skip, and it's often the most useful. Existing customers, competitors, companies you've already talked to, industries you won't serve. A good exclusion list saves more wasted outreach than a clever inclusion list.
Where profiles usually go wrong
Too broad to be useful. A profile that matches half the internet will produce a list that matches half the internet. Narrow is not a limitation here — it's what makes the list worth reading.
Describing the dream, not the reality. Many founders write the ICP of the customer they wish they had — the big logo, the enterprise account. Write the profile of who actually buys from you today. You can widen it later once that version works.
Titles that don't exist. "Growth decision-maker" is not a job title anyone has on their profile. Use titles people actually write, because that's what any search — manual or automated — will match against.
No exclusions. Without them, you'll reach your own customers, your competitors' sales teams, and companies that told you no last quarter.
What this looks like in practice
Here's a worked example — illustrative, not a real customer, just the method applied from start to finish.
A founder runs a 15-person agency that builds onboarding flows for software products. Their first draft of an ICP reads:
"Tech companies that care about user experience and want to grow."
Run the stranger test on it and it fails on every line. Rewritten using the five fields, it becomes:
- Industry: B2B SaaS - Company size: 20–150 employees - Geography: United States, United Kingdom, Canada - Job titles: Head of Product, VP of Product, Head of Growth - Exclusions: current clients, companies with an in-house design team over 5 people, agencies
Same business, same intent. The difference is that the second version can be handed to anyone — or any system — and turned into an actual list of named people at actual companies.
Start narrow, then widen with evidence
The instinct is to cast a wide net so you don't miss anyone. In practice, a narrow profile teaches you faster. Run it, see who responds, and look at what those people have in common. That pattern — not your first guess — is what tells you where to widen.
Treat your ICP as a draft you revise every few weeks, not a document you write once and file away.
The short version
A usable ICP is five searchable fields: industry, company size, geography, job titles, and exclusions. If a stranger couldn't build a list from it, it isn't done yet. Start with who actually buys from you today, keep it narrow, and let real responses tell you where to go next.
If you'd rather hand the list-building part off entirely, that's what Agenclaw's lead generation does — you describe the profile, it finds and verifies the matching decision-makers. What that costs per verified lead is on the pricing page, or you can start a run — no card, no call.