Company Data API: A Practical Guide for Builders

A company data API answers one question over HTTP: given a domain, a URL or a work email, which company is this, and what do we know about it? A good one returns a small set of firmographic fields such as name, industry, size band, location, phone and a LinkedIn page, and it says plainly when it has nothing. That last part matters more than most buyers expect.

The category is crowded and the marketing is loud. Some vendors sell people data and intent signals, some sell registry extracts, some sell a database you query with filters. Before choosing, decide what job the data must do. Enriching a signup form needs fast single lookups. Cleaning a CRM needs bulk calls and a way to spot dead websites. Building prospect lists needs search by industry, country and headcount. Feeding an AI agent needs the same data exposed as a tool.

If you want one concrete, documented example to study, the BusinessMCP Company Data API exposes five REST endpoints (lookup, bulk lookup, website status, email pattern and search), each also available as an MCP tool with the same price. Its page states that you pay only when a company is found and that company-level data is all you get: no people, no personal email addresses. You can try the free company lookup tool on the same site before creating a key, and the full API reference lists the schemas.

This publication is organised by the decisions you will face.

• Getting started. Read how to get company data through an API and the explainer on turning a domain into a company record.
• Wiring it in. See integrating company data into a CRM, enriching signups from work emails and bulk lookups.
• Buying well. Compare pricing models, enrichment API options and the best providers by use case.
• Edge cases. Understand real-time claims, website status checks and agent access over MCP.

One rule runs through every article: treat an API answer as a record with a source and a date, not as the truth. Small and new companies are often missing, size bands are estimates, and a miss should be stored as unknown rather than guessed. Teams that build around misses end up with cleaner data than teams that assume coverage.

We are independent. Where a product is discussed we say what it does, who it suits and what it lacks, and we link to its own pages so you can verify. Prices and features change, so always confirm on the vendor’s page, which for BusinessMCP is the data API overview.