How to build a prospect universe using AI
By Dave Curran, Co-Founder, Firmbase | March 2026 | 11 min read
Building a target account list is one of those things that sounds simple in theory and becomes a nightmare in practice.
"Find all the companies that match our ICP" - easy enough. You know who your customer is. You know their industry, size, location. You know what they care about.
Then you actually try to find them.
You search a list-building tool. You configure filters. You get a list of 5,000 companies. You look at the first 20. Half of them aren't actually relevant. So you add more filters to narrow it down. Now you've got 300 companies, but you're probably missing half the market because your filters are too restrictive.
This article walks through a better framework: define and discover, score and prioritise, research and action.
Stage 1: Define and discover using natural language
The first problem with filters is that they assume standardisation. They assume that official categories (like SIC codes) tell you what companies actually do. They don't.
Natural language search flips this on its head. Instead of filtering on SIC codes and standardised fields, you describe what you're looking for in plain English: "digital marketing agencies in the South East with revenue between £2M and £8M."
The system doesn't just filter on SIC code and location. It reads company websites, understands what they actually do, and surfaces companies that match. The quality is immediately better. You're not sorting through a list of false positives.
Stage 2: Score and prioritise using signals
Once you've discovered your universe - let's say 2,000 companies that actually match your ICP - the next problem is: which 200 should you actually target first?
This is where signals matter. The strongest signals are structural changes:
Companies House filings: Recent revenue growth, cash position changes, and director appointments.
Director appointments: A new finance director usually signals upcoming fundraising or growth acceleration. A new commercial director signals revenue focus.
Job postings: Multiple new postings in revenue roles signals scaling. New ops hires signal process maturity.
Funding announcements: Seed round, Series A, growth capital - all signal growth mode and budget availability.
The key point: don't just look at one signal. Weight them. A company with three signals (new finance director, growing revenue, hiring SDRs) is definitely worth your time first.
Stage 3: Research each priority account in depth
This is where most teams break down. You've got a prioritised list of 100 accounts. Now you need to know why you're reaching out to each one.
The traditional approach: spend 30-45 minutes per account researching. Do that for 100 accounts and you've lost 50-75 hours.
That's where AI agents come in. An AI agent can do that research in 2-3 minutes per account:
Input: company name, Companies House number, website URL, description of what you sell.
Process: The agent reads the company's website, cross-references their job postings, pulls their Companies House filing, synthesises all of that and identifies why this company might need what you're selling.
Output: A structured research brief with outreach angle.
Multiply that by 100 accounts. You're saving 50 hours and getting better, more contextual outreach.
Why this framework works at scale
Most teams find that once they've done this once, the process becomes continuous. Every month, new signals emerge: new directors appointed, new growth visible in filings, new job postings. You rescore your list. Instead of "we need to rebuild our target list," it's "we need to update our priority ranking based on this month's signals."
That's a running system, not a project.
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FAQ
How do I get accurate data about director appointments?
Companies House filings are the source of truth for UK director changes. They're public record and updated regularly (within two weeks of filing).
Should I weight all signals equally?
No. A director appointment + funding announcement + job postings is a stronger signal than just job postings. You're looking for convergence.
How often should I rescore my universe?
Monthly is realistic. New director appointments happen continuously, accounts file new financial reports, job postings change.
Author Bio
Dave Curran is the co-founder of Firmbase, a UK B2B sales intelligence tool that helps sales teams find, prioritise, and reach the right accounts without needing a RevOps team to make it work. Start your free trial