Key takeaways:
- Firmographic APIs split into two markets that rarely overlap. GTM providers optimize for coverage and speed; KYC providers optimize for provenance and audit trails, and only one of those will satisfy a compliance review.
- Check the source before the field list. Registry-derived data can be cited to a filing, inferred data cannot, and that distinction is the whole purchase for regulated use.
- Published prices are unusually clear at the low end and absent at the high end. OpenCorporates starts at GBP1 per 100 credits, BuiltWith at $295 a month, while HG Insights and Dun & Bradstreet publish nothing.
- Technographics are a separate field set sold by separate vendors. Nothing here returns firmographics and a full technology stack from one call.
Firmographics are the boring fields that decide everything downstream: industry, employee count, revenue band, location, legal entity, incorporation status. Every scoring model, routing rule and territory assignment runs on them, and every one of those breaks quietly when the fields are wrong.
The complication is that two different industries buy a firmographic api for opposite reasons. A growth team wants breadth and freshness to size a market. A compliance team wants a verifiable chain back to a government filing. This guide covers both, because the same search term serves both and the wrong choice fails expensively.
Nine providers are compared below, with pricing read off each vendor’s own page and quote-only vendors named as such rather than filled in with a guess.
What Is a Firmographic API?
A firmographic API returns descriptive attributes about a company rather than about a person. The core fields are consistent across vendors: legal and trading name, industry classification, employee count, revenue estimate, headquarters and other locations, founding date, and corporate structure.
Where providers diverge is provenance, and it is the only thing that matters for regulated work. Registry-derived data comes from official filings, so a record can be traced to a document with a date on it. Inferred data is assembled from web crawling, job postings and models, which produces much broader coverage and no citable source.
Resolving a domain to a canonical company record is a distinct job from describing one, and our roundup of company enrichment APIs covers that side of it.
Neither is better in the abstract. A market-sizing exercise wants the inferred provider’s coverage. A customer onboarding check wants the registry provider’s paper trail, because “our vendor estimated it” is not an answer a regulator accepts.
The compliance framing is not optional in the US. FinCEN’s Customer Due Diligence rule requires covered financial institutions to identify and verify the beneficial owners of legal entity customers, which means firmographic data used in onboarding has to be defensible rather than merely accurate.
The Best Firmographic APIs
The second column decides which half of this market a vendor belongs to, and it is the first thing to check against your use case.
| Tool | Data source | Best for | Main limitation | Pricing (from) | Rating |
| Reply.io | Inferred, GTM-oriented | Finding and contacting matching companies | No domain-to-firmographics endpoint | $49/month | ★★★★☆ |
| OpenCorporates | Official company registries | Traceable legal entity data | Coverage is entity-level, not commercial | GBP1 per 100 credits | ★★★★★ |
| Middesk | Registries plus verification workflow | Onboarding and KYB checks | No published pricing | Quote only | ★★★★★ |
| Enigma | Registries plus transaction signals | Small business revenue evidence | Complex per-call pricing | $0.01 per call | ★★★★☆ |
| Dun & Bradstreet | Proprietary D-U-N-S database | Enterprise-wide entity resolution | Publishes no pricing at all | Quote only | ★★★★☆ |
| TheirStack | Job-posting inference | Firmographics with hiring signal | Inferred, not registry-backed | $59/month | ★★★★☆ |
| BuiltWith | Website crawling | Firmographics tied to web technology | Per-call API pricing is quoted separately | $295/month | ★★★★☆ |
| Wappalyzer | Website fingerprinting | Cheap technology-plus-company lookups | Included API credits expire in 60 days | $250/month | ★★★☆☆ |
| HG Insights | Proprietary IT spend research | IT budget and spend estimates | Quote only, enterprise-oriented | Quote only | ★★★★☆ |
Read that table against your compliance obligations first and your coverage needs second, because a provider that cannot cite a source will not survive an audit no matter how complete its records are.
Reply.io
Best for: Acting on firmographic filters, not resolving them
Overview: Our place in this list is narrow and worth stating before anything else. We have no endpoint that accepts a domain and returns a firmographic record. If that is the call you need to make, several providers below sell exactly it and we do not.
What we do have is firmographic filtering across a large company footprint. Our contact database covers more than 60 million company profiles across 150-plus countries, and industry, location and headcount work as search filters rather than as a retrievable record.
That makes us useful at the other end of the workflow. Once a firmographic definition exists, we find the people inside those companies and run the outreach, on one credential.
The honest limits: the Live Data search endpoints carrying those filters are all marked Beta, and the five contact enrichment endpoints remain Coming soon in our developer docs as of August 2026.
Key features:
- Industry, location, seniority and headcount available as ICP search filters
- Typeahead endpoints that resolve firmographic filter values to valid IDs
- People search returning contacts at companies matching the definition
- Sequence endpoints that contact those people without an export step
- Native CRM syncs writing results back to HubSpot, Salesforce and Pipedrive
- Throughput capped at 100 requests a minute and 3,000 an hour, documented
Pricing: The entry point is $49 a month billed annually against 1,000 active contacts, with cost scaling on database size rather than seats. The base plan includes only 50 live data credits a month, so real volume needs a package from $20 a month. A 14-day trial is available and no plan is free.
Pros: large company footprint behind the filters, filtering and outreach on one contract, published throughput, CRM write-back, live validation endpoints
Cons: there is no domain-in, firmographics-out endpoint, so company attributes exist only as filters inside a beta people search, and the base plan’s 50 monthly credits will not support real volume
How to start using it:
- Sign up for the trial and create a v3 token under Settings, then API Key.
- Map each firmographic criterion onto a filter ID with the lookup calls.
- Submit a Live Data search carrying those filters and poll for completion.
- Put the returned addresses through validation before trusting them.
- Load the remainder into a sequence and subscribe to the reply event.
Why it’s a good firmographic API companion: It turns a firmographic definition into contacted people, which is the step that firmographic data usually exists to enable.
Final verdict: Right when you already have a company definition and need to act on it. Wrong if you need to resolve a domain into a company record, which we do not offer.








