Fair use

Last updated September 25, 2026. This page is part of the Acceptable Use Policy and the Terms of Service.

Three different things get confused with each other constantly, so they are kept apart below: how fast you can call the API, how many envelopes you can send, and what makes us take a look at an account.

API rate limits

25 requests per second sustained, bursting to 100, per workspace. Go past it and the API replies 429 with a Retry-After header telling you how long to wait. Nothing is lost; retry after the interval.

Each of our servers counts your requests separately, so a burst above the limit can sometimes succeed. Build for the published numbers, not for what happens to get through.

Applies to: API requests per tenant.

Monthly volume

There is no volume cap. Live envelopes are billed per completed envelope: the monthly minimum covers your first 134, and each one after that is billed at the per-envelope rate. See pricing for the numbers. Nothing pauses sending because of volume, with one exception the terms describe: after you cancel, new live envelopes are refused for the rest of the month once the month's completed and in-progress envelopes reach what your minimum covers. Test envelopes are free and are never counted.

Envelopes already sent can still be signed while a payment is late and after you cancel. Only closing an account for non-payment voids the ones still out. Documents already signed stay downloadable as the terms describe.

Automated review

Sending more than 2,000 live envelopes in one day (UTC) flags the account for a person to look at. Single sends and bulk batches count the same way: a batch that would take the day past the threshold is flagged when it is sent, and it still goes out.

Crossing this flags the account for automated review. It is not a limit, not a charge, and never stops a send.

The point of the threshold is shape, not size: it sits well above an ordinary month of sending spread across a month, so crossing it means a month of envelopes arrived in a day. Usually that is a busy week landing at once, and nothing happens. It is worth looking at anyway, because the same pattern is what a compromised key looks like. What happens after a review is set out in the Acceptable Use Policy.

What is not allowed

Bulk sending of transactional envelopes your recipients expect is a supported feature, and we do not limit it by volume. What the Acceptable Use Policy prohibits is unsolicited or promotional content dressed up as a signature request, sending to people who have not agreed to deal with you, and getting around these limits, for example by spreading the same sending across several accounts.

If you need more

These limits suit ordinary use of the product. If your integration needs a higher sustained rate, write to support@signenvoy.com before you hit it rather than after.