B2B contact databases all claim to be the largest and most accurate. In practice, email accuracy in most databases is 70-85% - meaning 15-30% of addresses you download will either not exist, not be deliverable, or belong to the wrong person. This guide compares the top B2B contact databases on data quality, explains what “accuracy” claims actually mean, and tells you what to look for and what to avoid.
Most databases claim 95%+ accuracy. In practice, independent tests consistently show 70-85% deliverability on exported lists. The gap exists because:
Not that the mailbox currently accepts email. Format verification (checks the @ and domain structure) is trivial. Deliverability verification (actually probing the SMTP server) is what matters.
B2B contact data has an estimated 25-30% decay rate per year. People change jobs, companies close, roles change. A database with 90% accuracy at time of collection may be 75% accurate 12 months later.
Many company email servers accept email for any address at the domain, even invalid ones. A database can “verify” these as deliverable - but the email may not actually reach anyone.
Vendor accuracy claims are based on their own methodology, which may use format verification, proprietary scoring, or cherry-picked datasets. Always test a sample before buying.
| Database | Contacts | Real email accuracy | Price | Best for |
|---|---|---|---|---|
| Apollo.io | 300M+ | 70-82% | $49-119/mo | High-volume prospecting, best price per contact |
| ZoomInfo | 300M+ | 75-85% | $15K-30K+/yr | Enterprise teams needing intent data + contacts |
| Clay (waterfall) | 75+ sources | 80-92% | $149-800/mo | Max find rate via multi-source waterfall |
| Hunter.io | 100M+ | 72-85% | $49-149/mo | Individual email finder + domain search |
| Lusha | 200M+ | 72-82% | $29-51/mo | SMB prospecting, affordable for small teams |
| FindyMail | Unknown | 78-85% | $49-99/mo | Highest accuracy per-lookup, not a large database |
| Cognism | 400M+ | 73-84% | $15K-25K/yr | EMEA coverage + phone-verified mobile numbers |
| Snov.io | 150M+ | 68-78% | $39-189/mo | Affordable, built-in sending tool + email finder |
Lists sold at this price point are typically scraped, unverified, and extremely stale. Expect bounce rates of 30-60%. They damage your domain reputation immediately.
Legitimate databases verify data before export. If a vendor offers instant CSV download of millions of contacts with no verification step, the data has not been quality-checked.
If a vendor cannot explain how they collect data and comply with data privacy laws, you are buying data of unknown provenance. This is a legal risk in addition to a deliverability risk.
Some tools scrape contact data from LinkedIn or other platforms without authorisation. Data from these tools violates platform terms of service and often GDPR.
Even the best database (Clay waterfall at 80-92% accuracy) leaves 8-20% potentially undeliverable. Verify every export before it reaches your sending tool. 100 free credits, no card required.
Apollo, ZoomInfo, Lusha and Cognism all have accuracy gaps - verify exports before sending
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