A B2B data API is an interface that lets you pull company and contact data directly into your own systems, on demand. Instead of exporting CSVs and uploading them by hand, you query the provider and get structured data back in real time. The right one fills your CRM, powers your enrichment waterfall, and keeps your outbound list accurate without manual work.
The wrong one drains budget and still leaves blank fields. This guide compares the 7 best B2B data APIs for 2026, what each one is actually built for, what it costs, and where it falls short. We lead with our pick, then give you an honest look at every serious alternative.
What does a B2B data API do?
A B2B data API delivers company and contact data to your application through structured requests, usually in JSON. You send an input, such as a domain, a LinkedIn URL, or an email, and the API returns enriched fields like firmographics, job titles, verified emails, and mobile numbers.
There are three common jobs a B2B data API handles. The first is enrichment, where you add missing fields to records you already have. The second is search, where you find new companies or contacts that match a filter. The third is verification, where you check that an email or phone number is still valid before you use it. The best B2B data providers do all three through one endpoint.
What should you look for in a B2B data API?
Look for verified contact data, broad coverage, transparent pricing, and integrations that match your stack. Coverage and accuracy decide whether your campaigns reach real people. Pricing decides whether you can afford to run them at scale.
These are the criteria that separate a strong B2B data API from a weak one:
- Data type. Does it return only firmographics, or also verified emails and mobile numbers? A company data API or business information API returns the organization. A contact data API returns the person. Outbound teams need both.
- Verification. Is the data checked before delivery, or do you verify it yourself afterward?
- Coverage and fill rate. What percentage of your list comes back enriched, not blank?
- Pricing model. Credit-based and pay-as-you-go scales with you. Seat-based enterprise contracts do not.
- Integrations. Native connections to Clay, Instantly, HubSpot, and Salesforce save engineering time.
- Compliance. GDPR, CCPA, and SOC 2 alignment matter if you sell into regulated markets.
What is the best B2B data API in 2026?
Scalelist is the best B2B data API for outbound and enrichment teams in 2026, because it returns waterfall-verified emails and mobile numbers from one endpoint, with transparent credit pricing that starts free. Most alternatives give you either company data or contacts, force an annual enterprise contract, or lock you into a single ecosystem. Scalelist does none of those things.
The right pick depends on the job. If you want the best B2B enrichment API for cold outreach, you need verified contacts and high fill rates. If you want a data enrichment API to keep your CRM clean, you need real-time accuracy and native integrations. The seven providers below cover both use cases, ranked by what each does best.
Below is the full comparison. We ranked each provider by what it is best at, not by a single score, because a developer licensing datasets and an SDR filling a sequence need different things.
Comparison table: 7 best B2B data APIs
| Provider | Best for | Verified email + mobile | Entry price | Pricing model |
|---|---|---|---|---|
| Scalelist | Outbound + Clay/Instantly enrichment | Yes, both | Free (50 credits) | Credit-based, pay-as-you-go |
| Cognism | Enterprise EU/US sales orgs | Yes (phone-verified) | ~$17,000/yr | Seat + DaaS contract |
| Coresignal | Developers building data products | No (company data) | $49/mo | Credit-based |
| People Data Labs | Engineers licensing datasets | Partial (unverified) | Usage-based | Pay-as-you-go / license |
| Clearbit (Breeze) | HubSpot-native teams | Email yes, mobile limited | HubSpot credits | Bundled in HubSpot |
| Bright Data | Web data at scale | No (infrastructure) | Usage-based | Usage-based |
| CompanyData.com | Company verification / KYB | Contacts, not verified | €425 | Dataset purchase |
1. Scalelist (best overall B2B data API)
Scalelist is a B2B contact data and enrichment API that returns verified work emails and mobile numbers at scale. You send a LinkedIn URL, a domain, or a CSV, and Scalelist runs a waterfall across 10+ data sources to find the contact, then verifies the email before it returns it.
That waterfall is the key difference. Single-source tools return a blank whenever their one provider does not index a contact. Scalelist checks many sources in sequence, so fill rates stay high. Every email comes back labeled Valid or Risky, so you protect your domain reputation before a single message sends.
Key features:
- Verified email enrichment at 1 credit per result, with bundled verification included.
- Mobile number enrichment through the same API, with no separate tool required.
- Waterfall sourcing across 10+ providers for higher fill rates than single-source APIs.
- Native integrations with Clay, Instantly, HubSpot, Salesforce, n8n, and Make.
- Job-change monitoring that alerts you when a tracked contact moves company.
- Built in the EU, aligned with GDPR.
Pricing: Free plan with 50 enrichment credits. Paid plans start at $99 per month for 5,000 credits. Emails cost 1 credit, mobile numbers cost 20 credits. Pay-as-you-go, no annual contract, no seat minimum.
Where it fits: outbound teams, agencies, and RevOps functions that need send-ready contacts inside Clay or Instantly without a data-engineering project. Coverage depends on LinkedIn indexing density, which is the honest ceiling for any LinkedIn-first enrichment tool.
2. Cognism
Cognism is a sales intelligence platform with a company data API delivered through its Data as a Service offering. It is known for phone-verified mobile numbers and a strong compliance posture, which makes it a fit for large EU and US sales organizations.
Key features: API and flat-file delivery through Snowflake, S3, and other warehouses. Audit-ready metadata with a GDPR, CCPA, and PECR consent trail. SOC 2 Type II and ISO 27001 certification.
Pricing: Cognism’s DaaS requires a minimum Pro seat that starts at roughly $17,000. There is no free tier and no self-serve pay-as-you-go.
Where it fits: enterprise teams with budget and a compliance mandate. The price floor and annual commitment put it out of reach for most small and mid-market teams.
3. Coresignal
Coresignal is a public web data provider with a company data API covering 67M+ company profiles and 300+ data points per record. Data comes as structured JSON and supports Elasticsearch Query DSL for advanced filtering.
Key features: firmographics, workforce, funding, and online-presence data refreshed from public web sources. Search and enrich flows with flexible querying.
Pricing: starts at $49 per month, credit-based, with free credits to start.
Where it fits: developers and data teams building products on top of company data. It is firmographic intelligence, not a prospecting tool. It will not return a deliverability-verified email and mobile for a named person, so outbound teams still need a contact-data layer on top.
4. People Data Labs
People Data Labs is a person and company data API built for developers, offering dataset licensing and flexible, usage-based access to billions of records. It is a strong choice when you want to build data into your own product.
Key features: developer-first API, person and company enrichment, and dataset licensing for bulk use cases.
Pricing: usage-based and pay-as-you-go, priced for engineering teams.
Where it fits: product and data teams with engineering resources. The data is raw, so verification and deliverability are your responsibility. For a sales team that just wants to fill a sequence, that is a project, not a plug-in.
5. Clearbit (HubSpot Breeze Intelligence)
Clearbit, now part of HubSpot as Breeze Intelligence, is a real-time enrichment API tightly integrated with the HubSpot ecosystem. It enriches forms and records the moment data enters your CRM.
Key features: real-time record and form enrichment, firmographic and demographic data, and deep native HubSpot workflows.
Pricing: delivered through HubSpot credits, bundled into the HubSpot platform.
Where it fits: teams that live inside HubSpot. The value drops sharply outside that ecosystem, and mobile-number coverage is limited compared with dedicated contact-data providers.
6. Bright Data
Bright Data combines proxy networks, scraping tools, and ready-made datasets. It is infrastructure for collecting web data at scale, not a contact database.
Key features: residential, ISP, datacenter, and mobile proxies, plus scraping tools like the Scraping Browser, Web Scraper IDE, and SERP API. Structured datasets available on request.
Pricing: flexible, usage-based, with custom quotes.
Where it fits: engineering teams that need custom web data at volume. It sits at the wrong layer of the stack for an SDR who just needs verified emails and mobiles.
7. CompanyData.com (Bold Data)
CompanyData.com, by Bold Data, is a global company and contact data provider with an API covering 303M+ companies and 287M+ contacts, refreshed with 600k+ new records each month.
Key features: registration details, incorporation data, ownership structure, and contact information. Strong for company verification and KYB.
Pricing: starts from €425, depending on the datasets you need.
Where it fits: teams that need registry-grade company data for verification and compliance. The records are static and not built around a verification waterfall, so they suit due diligence better than cold outreach.
B2B data API vs DaaS: what is the difference?
A B2B data API gives you direct, real-time access to query or enrich records, while Data as a Service (DaaS) is a broader managed program with multiple delivery methods and advisory support. An API is focused and lightweight. DaaS adds flat-file delivery, ongoing validation, and a service contract around the data.
For most outbound and growth teams, a self-serve API is the better starting point. You get value in one call, with no procurement cycle. DaaS makes sense when you need warehouse-scale delivery and a managed compliance program, which usually means an enterprise budget.
How much does a B2B data API cost?
B2B data API pricing ranges from free entry tiers to enterprise contracts above $17,000 per year. Self-serve providers like Scalelist and Coresignal use credit-based pricing that starts free or near $49 to $99 per month. Enterprise platforms like Cognism use seat-based DaaS contracts with a high annual floor.
The model matters more than the headline number. Credit-based, pay-as-you-go pricing lets you match spend to usage and test before you commit. Seat and contract pricing locks you in for a year regardless of how much data you pull.
Is a B2B data API GDPR compliant?
A B2B data API can be GDPR compliant, as long as the provider collects only business-related data with a lawful basis and gives you a consent and sourcing trail. Compliance is a property of the provider, not the API itself. Check for GDPR and CCPA alignment, and for certifications like SOC 2 Type II or ISO 27001 if you sell into regulated markets.
Scalelist is built in the EU and aligned with GDPR. Cognism adds CCPA, PECR, SOC 2 Type II, and ISO 27001 for enterprise compliance needs.
FAQ
What is a B2B data API?
A B2B data API is an interface that delivers company and contact data to your software through structured requests. You send an input like a domain or LinkedIn URL, and it returns enriched fields such as firmographics, job titles, verified emails, and mobile numbers in real time.
What is the best B2B data API for outbound?
Scalelist is the best B2B data API for outbound, because it returns waterfall-verified emails and mobile numbers from one endpoint and plugs natively into Clay and Instantly. It starts free, so you can test coverage on your own list before committing.
What is the difference between a company data API and a contact data API?
A company data API returns firmographic information about an organization, such as size, industry, and funding. A business information API means the same thing. A contact data API returns information about a person, such as their verified email and mobile number. Tools like Scalelist combine both, so you can go from a company to a send-ready contact in one call.
Can I use a B2B data API with Clay?
Yes. Scalelist integrates natively with Clay, so you can enrich a Clay table with verified emails and mobiles without writing code. It also connects to Instantly, HubSpot, Salesforce, n8n, and Make.
How accurate is B2B data API data?
Accuracy depends on verification and sourcing. APIs that verify emails before delivery and waterfall across multiple sources return higher fill rates and fewer bounces. Scalelist verifies every email at enrichment and labels it Valid or Risky before it reaches your sequence.
The bottom line
The best B2B data API depends on the job. For outbound and enrichment, you want verified emails and mobiles, high fill rates, and pricing that scales with usage, which is where Scalelist leads. For raw firmographics or custom web data at scale, Coresignal and Bright Data fit. For enterprise compliance programs, Cognism fits.
If your goal is to fill campaigns with contacts that actually reach a human, start with a waterfall contact API and test it on your own list. You can enrich your first 50 contacts free and see the fill rate before you spend anything.
