Short answer: No. When we detect that an address belongs to a disposable (throwaway / temporary) email service, the result is returned to you free of charge. The one exception is if you explicitly run a full live SMTP check on the address — see "When a disposable check is billed" below.
What counts as disposable
Disposable addresses come from temporary-inbox services (e.g. 10-minute-mail–style providers) that people use to sign up without giving a real, lasting address. These addresses are technically "real" for a short time but are not useful for ongoing communication, so we flag them as disposable.
Why it is free
Detecting a disposable domain does not require a live mailbox probe — we recognize the provider directly. Since there is no meaningful verification work to bill for, and the result is really a "don't bother sending here" signal, we do not charge a credit for it. This is consistent across every entry point: single verification, bulk, and file uploads all treat disposable hits the same way.
The free dedicated endpoint
If all you want is a disposable check, there is a dedicated endpoint for it that is always free and does exactly this one job. It is a convenient way to screen addresses without spending credits.
When a disposable check is billed
There is one exception, and it follows a clear rule: if an actual live SMTP verification was performed, that check is billable — and SMTP billing takes priority over the free treatment of disposables.
In normal use we identify a disposable address from its domain, with no SMTP probe, so there is no charge. But if you explicitly request a full SMTP verification (via the check_smtp option) and we complete that live check on the address, it is billed like any other SMTP verification — even though the address is disposable. You are charged in that case because real verification work was actually performed at your request; the disposable "free" rule does not override a completed SMTP check.
The dedicated disposable endpoint never does this — it does not allow SMTP checks, so it is always free.
What we recommend
Treat disposable addresses as not worth sending to: they will usually stop working within minutes to hours. It is safe to exclude them from your list. And because the check costs you nothing, screening for disposables is a free way to clean your data before you spend credits on the addresses that matter.