Email Verification API Pricing for Developers: What $39 a Month Includes

The SimpleVerifier API is included with the Pro plan at $39 a month: 10,000 calls a month, then $1.50 per 1,000 on monthly billing. That is the whole price. There is no separate API subscription, no per-seat key fee and no credit pack to run out of. This post explains what a call is, how to estimate yours, what the rate limit means for your code, and the situations where another vendor is cheaper.

What a call is

The unit of billing is the call, not the address. That matters for how you design.

• One HTTP request to the verify, phone or list endpoints is one call. Checking one address is one call.
• Starting a list job is one call, however many addresses it holds, up to 100 per job.
• Reading a list job's results is one call. A result page can hold up to 500 rows.
• MCP tool calls count the same way. A verify_email call is one call; a verify_emails call with up to 100 addresses is one call.
• Free: your usage endpoint, listing your jobs and MCP handshakes cost nothing.
• Months are counted in UTC. Calls reset on the 1st.

The consequence: batching is cheaper in calls. Verifying 100 addresses one at a time is 100 calls. Verifying them as one list job is two (start, read). If your integration processes batches, use the list endpoint. If it reacts to one signup at a time, use the single endpoint. The quickstart and API reference show both.

What the plans include

Plan	Price	API calls included	Past the included calls
Starter	$9 a month	None	Not available
Pro	$39 a month	10,000 a month	$1.50 per 1,000
Business	$99 a month	100,000 a month	$1.00 per 1,000
Agency	$249 a month	300,000 a month	$1.00 per 1,000

Billing interval changes the overage behaviour. On monthly billing, calls past the included ones are metered and added to the next invoice. On yearly billing, the included calls are a fixed monthly quota, and further calls return a 402 with a Retry-After until the 1st (UTC). Plan features beyond the API, the finder, enrichment and the verification volume, are in pricing.

Estimating your calls

Work from the event that triggers a check.

A signup form verifying each new account. One call per signup. 6,000 signups a month is 6,000 calls: inside the included 10,000. 25,000 signups is 25,000 calls: 15,000 over, which is 15 x $1.50 = $22.50 on top of $39 on monthly billing. Our guide to API cost per month walks through the same maths from your signup numbers, and validating an email in your signup form covers what to do with the answer.

A workflow tool such as Clay, Make or n8n. One call per row if it calls the single endpoint, far fewer if it batches into list jobs. Set the tool's own throttle to about 100 calls a minute, under the key's 120, so you do not hit 429s. See verifying emails in n8n.

An AI agent. Each tool call is a call. An agent that checks a handful of addresses per task uses very few; an agent looping over thousands one by one uses thousands. Give it the batch tool. We cover the setup in the MCP docs and email verification for AI SDR agents.

A nightly job over new leads. One list job per 100 leads, plus a results call: roughly 2 calls per 100 leads. 20,000 new leads a month is about 400 calls.

Rate limits and what they mean for your code

• 120 calls a minute per key, over a sliding 60-second window. Past it the API answers 429 with a Retry-After header and the same number in the body as retry_after_seconds. Wait that long, then retry.
• One mailbox check can take up to 30 seconds when a mail server is slow. Set your client timeout above that and do not retry in a tight loop.
• List jobs wait up to 45 seconds for results before returning the job id. Poll the job for the rest rather than holding the connection.
• Lists over 100 addresses go through the dashboard. A CSV upload on the verify page runs the same checks in bulk without using API calls at all.

For the error codes, including 401, 402 and 429, see the error reference. Our post on rate limits covers retry patterns, and API or CSV upload helps decide which of the two you need.

What the API returns

A verify call returns a status of valid, risky or invalid, a reason in words and a stable reason code, a flag for whether the mailbox was actually checked and confirmed, and a plain-English action: send or do not send. You can branch on the status without parsing text. The SMTP check runs inside the same call as the syntax and domain checks. See the API docs for the full response, and real-time verification API for latency considerations.

When another vendor costs less

Be straight about the comparison, because the cheapest option depends on your shape.

• Very low API volume. If your integration makes 1,000 calls a month and nothing else, a per-check vendor with a pay-as-you-go pack may cost less than $39. A monthly plan charges for months you barely use.
• No dashboard needs. If you will never upload a CSV, use the finder or touch the other features, you are paying for more than you use.
• Single-address-only at very high volume. If every check is one call and you run hundreds of thousands a month, calls cost $1.50 per 1,000 on Pro, and Business ($99) lowers that to $1.00 per 1,000 after 100,000 included. Compare that with a per-check vendor's price for the same volume.

We do not quote competitor prices here, because they move. Take each vendor's price from its own pricing page on the day you decide. Our API comparison and pricing index point to the explainers, and the credits vs monthly plan calculator takes any prices you type.

When the flat plan wins

The API is not sold alone on SimpleVerifier. It sits on top of a plan that already covers a lot, so the case for Pro is the sum of what you use:

• The first 100,000 email checks a month at full speed, then slower, never cut off, through CSV uploads in the dashboard, for the lists too big for the API.
• The API and MCP: 10,000 calls a month included.
• The email finder and website enrichment from the same account.
• Real SMTP mailbox checks, catch-all, disposable and role detection on every call.

If you use the API for live checks on a form and the dashboard for the weekly list, you pay once. A flat-rate plan makes more sense the more of those you use. If you only need Starter's CSV checks, see Starter or Pro.

Getting started

1. Try the free checker at /tools/verify-email for single addresses with no account, to see the output shape.
2. Sign in with Google at /verify for 100 free checks on a list.
3. Take Pro when you want a key, then create it on the keys page and follow the quickstart. There are code samples in the SDK guide and in posts for Python and a Cloudflare Worker.

Pro is $39 a month with 10,000 API calls included and the first 100,000 email checks a month at full speed, then slower, never cut off. See pricing.