Email verification cost is quoted per check. The useful number is per usable contact
Every verification price list is written per check, per credit or per seat. None of those units is the thing a cold email team actually buys, which is a mailbox that accepts mail from a named person today. The gap between the two is where verification budgets quietly disappear: you are billed for the check whatever answer it returns.
Three billing models, three different units
| Model | What you are billed for | Where the money leaks |
|---|---|---|
| Credits per check | Each address submitted, valid or not | Every unknown, duplicate and typo still consumes a credit |
| Seat licence + credits | Named users per month, plus a credit balance | Unused seats in a quiet month, and a top-up every busy month |
| Bundled with a database | Annual subscription, verification included | The included verification ages with the database rows it came with |
Published entry prices give the shape of each model: Apollo's Basic plan is listed at $49 per user per month on an annual commitment (apollo.io/pricing), Hunter starts from $34/month after 50 free credits and lists a Growth tier at $149/month (hunter.io/pricing), Lusha's Starter tier is listed at $49.90/month (lusha.com/pricing), and ZoomInfo does not publish prices at all. Those numbers describe the entry point of each model, not the cost of a usable contact inside it.
The four lines that are not on the invoice
- The unknown rows. An accept-all server answers the same for a real person and for an invented address, so the check returns
unknown— and it was still billed. A list can be 100% "checked" and still contain an unmeasured unknown share. - The decay clock. 40% of email addresses are dead within two years (NeverBounce) and 23% of business contacts change jobs annually (ZoomInfo, 2025). A verification result is a timestamp, not a property: the same list needs re-checking, and re-checking is a recurring cost line nobody forecasts.
- The bounce you send anyway. Sending to rows that were never truly verified costs deliverability, and deliverability is the asset with the longest replacement time. Static databases run 10–35% bounce rates against 2–5% for a list verified at the moment of use.
- The seat you do not need. Per-seat pricing charges for access, not for verification throughput; a two-person team pays for the same seat count as a ten-person team on most tools.
How to compute your own cost per usable contact
Take the monthly bill, add the top-up credits and the re-checks, then divide by the number of addresses you would actually send to. If a vendor cannot tell you how many of the checked addresses were valid versus unknown, the denominator is unknown and the price per usable contact is not calculable from their invoice alone. That absence is a pricing decision, not an oversight.
How TAPAC is priced
- Pay-per-use, $0.10–0.50 per verified contact — no seat licence, no separate enrichment line, no annual commitment.
- 100 free searches to measure the unknown share on your own market before paying anything.
- Verification is inside the search call, not a second tool:
POST /v1/contacts/searchscans the sources you allow and probes the mailbox over SMTP in the same request, so the row arrives with its verdict attached. Single addresses can be checked withPOST /v1/contacts/verify. - Catch-all domains are reported as
unknown, not as valid — you can see the segment you are not paying confidence for.
curl -X POST https://tapacapi.com/v1/contacts/search \
-H "Authorization: Bearer ***" \
-H "Content-Type: application/json" \
-d '{"industry":"logistics","job_titles":["head of operations"],
"company_size":"51-200","location":"poland","source":"website","limit":40}'
From an agent the same call is one tool: npx -y @tapacapi/mcp, or the hosted endpoint https://tapacapi.com/mcp, exposing tapac_find_contacts and tapac_status. Without a key the server returns onboarding instead of an error.
The honest limit. Verification proves the mailbox exists; it does not prove interest, and it does not make an offer relevant. SMTP probing is also rate-limited per domain, so volume needs pacing — the server does that, not the caller.
Where to go next
- Email verification cost · Lead enrichment API · Email verification API
- Email list cleaning · B2B email finder · B2B lead list · Catch-all verification
- Install the TAPAC MCP server — npx, uvx or the hosted endpoint, with the JSON block for Claude, Cursor, Codex and Windsurf.
- Compare TAPAC with Apollo, ZoomInfo, Hunter and Lusha · Pricing · Get a free API key