Email Verification API Pricing (2026): Real Per-1,000 Costs Compared
By Aria Pramesi, founder of InboxPolicy · Updated July 9, 2026
BLUF: Bulk list cleaning runs roughly $0.59 to $10.00 per 1,000 depending on vendor and volume tier; pay-per-call access, where it exists at all, runs about $0.01 per check where it exists at all. The trap isn't the per-unit price on the pricing page — it's the billing model underneath it: subscription minimums, credits that expire, and re-verification charges that bill full price for checking the same address twice.
"Email verification tool with an API that won't destroy my budget" is a common ask, and for good reason — verification bills routinely end up costing more than the outreach tool sending the mail. Usually that's not the sticker price failing; it's the billing model. This page compares nine vendors' actual pricing structures, not just their homepage numbers.
Vendor pricing matrix (as of July 2026)
Entry price is the smallest published tier; at-volume is the cheapest tier we could confirm. Cells marked "—" mean the vendor's pricing page didn't publish that detail, or we couldn't independently verify it as of this writing — check the vendor directly before relying on it. Sourced from our vendor comparison pages where available, live vendor pricing pages otherwise.
| Vendor | Entry price /1k | At-volume price /1k | Billing model | Credits expire? | Free re-verification? | Pay-per-call option? |
|---|---|---|---|---|---|---|
| InboxPolicy | $5.00 (Starter pack) | $3.16 (Growth, 25k) | Prepaid packs + keyless pay-per-call | — (not a lot-expiry model) | Yes — 72h cache, free | Yes — $0.01/call, USDC on Base, no account |
| ZeroBounce | ~$8.00 (list) | — (volume pricing available, not published) | Subscription (ZeroBounce ONE, ~$99/mo min 10k credits) + pay-as-you-go | No — never expire | — unclear (FAQ hints unknown results may not bill, unconfirmed) | No dedicated tier confirmed |
| NeverBounce | ~$8.00 (published entry rate, varies) | — | Pay-as-you-go credits | — | — | — |
| Kickbox | ~$10.00 (list) | — (not published) | Pay-as-you-go credits, one-time free credits at signup | — | — | — |
| MillionVerifier | ~$2.50 (small pack) | ~$0.59 (largest pack) | Pay-as-you-go credits | — | — | — |
| Emailable | — (no reliable public figure; 5,000-credit minimum purchase) | — | Pay-as-you-go or subscription (15% subscription discount) | No — never expire | Yes — duplicates and unknown results refunded | No |
| Hunter | ~$17.00 (Starter plan credit rate) | — | Subscription with monthly credits + add-on packs | Yes — bulk packs valid 12 months | Yes, within same calendar month | No — API tier still draws from a purchased credit pool |
| Clearout | — (not published on pricing page) | — (up to 20% subscription discount, no tier breakdown) | Subscription or pay-as-you-go credits | No — never expire | — | — (API exists, no standalone per-call price) |
| Bouncer | $8.00 (1,000 credits) | $2.00 (1,000,000 credits) | Pay-as-you-go credits | No — never expire | Yes — never charges for duplicates or unknowns | Separate API product, per-call rate not listed |
InboxPolicy figures are canonical (/pricing). ZeroBounce, NeverBounce, Kickbox, and MillionVerifier entry figures are the vetted numbers from our ZeroBounce, Kickbox, and MillionVerifier comparison pages; ZeroBounce's subscription detail and Emailable, Hunter, Clearout, and Bouncer figures come from live vendor pricing pages fetched for this article. Pricing changes — verify current rates before committing to a vendor.
The hidden costs
The per-check price on a homepage rarely predicts the bill. Four patterns cause most of the overage:
- Re-verification billing. Most bulk verifiers charge full price every time you check an address, even one you checked yesterday. A monthly cleanse on a list with heavy overlap means paying for the same addresses twelve times a year. InboxPolicy's 72-hour cache returns a repeat check for free; nothing else in this table advertises a comparable window.
- Credit expiry. Hunter's bulk credit packs are valid for 12 months from purchase — a large one-time pack can lapse before it's used. ZeroBounce, Emailable, Clearout, and Bouncer all advertise credits that never expire, the safer default for bulk buy-slow-use.
- Subscription and minimum-purchase floors. ZeroBounce's current ONE plan has a roughly $99/month minimum tied to 10,000 credits, whether or not you use them. Emailable requires a 5,000-credit minimum purchase. Neither fits a one-off check or a low-volume agent firing occasionally — you're paying for capacity you may not use.
- Unknown-result billing. A verification that comes back "unknown" or "catch-all" resolved nothing actionable, yet most vendors still bill it as a full check. Bouncer and Emailable explicitly don't charge for unknown/duplicate results; ZeroBounce's FAQ hints at similar treatment without confirming it. Ask before assuming your unknowns are free — on a list where 30-40% of B2B addresses sit on catch-all domains, unresolved results are a third of your list, not an edge case.
Cost by scenario
The cheapest vendor changes depending on what you're actually doing with it.
10,000-email list, one-shot clean
A single bulk clean with no repeat lookups is the scenario the homepage sticker price is built for. MillionVerifier is the honest budget pick: 10,000 × its published range works out to roughly $5.90-$25, depending on which volume tier that purchase lands in (the exact 10k breakpoint isn't published). InboxPolicy's Starter pack runs $50 for the same 10,000 at $5.00/1k — more expensive for a pure one-time clean, in exchange for a send-decision action and SMTP evidence instead of a status field.
50,000-email list, cleaned monthly on an ongoing basis
If the list has real overlap month to month, the math flips. Vendors that recharge full price on every repeat (ZeroBounce, Kickbox, MillionVerifier, NeverBounce as published) multiply the one-shot cost by every cleaning cycle. InboxPolicy's 72-hour cache only pays off if your cadence keeps stable addresses inside that window: for a list with genuine month-to-month churn, MillionVerifier's raw per-check price still likely wins; for a list that's mostly the same addresses re-checked before every send, InboxPolicy's free repeats win on cumulative cost. Model your own churn rate with the cost calculator.
An AI agent making 1,000 live send-decision calls
This is where account-based pricing breaks down. Bouncer's minimum purchase is 1,000 credits for $8; Emailable's minimum is a 5,000-credit purchase; ZeroBounce's plan floor is a ~$99/month subscription. None of that fits an agent that fires occasionally and shouldn't need a human to provision an account first. InboxPolicy's x402 pay-per-call is the only keyless option here: $0.01 in USDC on Base per call, no signup, $10 total for 1,000 calls, settling on-chain per request.
Frequently asked questions
How much does email verification cost per 1,000 emails?
For bulk list cleaning, expect roughly $0.59 to $10.00 per 1,000 verifications depending on vendor and volume tier: MillionVerifier's largest packs run near $0.59-$2.50/1k, InboxPolicy's packs run $3.16-$5.00/1k, and ZeroBounce, NeverBounce, and Kickbox list around $8-$10/1k. For pay-per-call access with no account, InboxPolicy's x402 rate is $0.01/call ($10/1k). The per-unit price is only half the story; billing model (subscription minimums, credit expiry, re-verification charges) often matters more than the headline rate.
What is the cheapest email verification API?
For a one-shot bulk clean of a large list, MillionVerifier's volume pricing (roughly $0.59-$2.50 per 1,000) is typically the cheapest listed rate. For a list that gets re-verified repeatedly over time, InboxPolicy is usually cheaper overall because re-checks inside its 72-hour cache window are free, while most bulk verifiers bill full price on every repeat lookup. "Cheapest" depends on whether you're paying once or paying monthly.
Do email verification credits expire?
It varies by vendor. ZeroBounce, Emailable, Clearout, and Bouncer all advertise that credits never expire. Hunter is the exception among vendors we could confirm: its bulk credit packs are valid for 12 months from purchase. InboxPolicy doesn't sell expiring credit lots; its packs are prepaid balances plus a $0.01 keyless pay-per-call option, and its 72-hour cache window is a re-verification discount, not a credit expiry policy.
Why is my email verification bill so high?
Three usual causes: re-verification charges (most vendors bill full price every time you re-check the same address, even a day later), minimum purchase or subscription floors (ZeroBounce's ONE plan requires a 10,000-credit monthly minimum around $99/mo; Emailable requires a 5,000-credit minimum purchase), and unknown or catch-all results still consuming a full credit even though the check didn't resolve anything actionable. A bill that looks disproportionate to your list size is usually one of these three, not the advertised per-check rate.
Is there a pay-per-call email verification API with no account?
InboxPolicy is the only vendor in this comparison with a genuinely keyless pay-per-call option: a request returns HTTP 402 with machine-readable payment terms, and $0.01 in USDC on Base settles the call with no signup. Hunter has a separate API-only Data Platform tier, but it still runs on a purchased credit pool rather than a per-call payment. Every other vendor compared here requires an account and a prepaid balance or subscription before the first API call.
Related resources
- Email verification cost calculator — model your own list size, bounce rate, and re-verification cadence.
- Best email verification API: how to choose
- Full vendor comparison hub
- InboxPolicy pricing
- Why InboxPolicy has no free tier
- API docs