Sending is paced at 20 messages per second per channel, and only one campaign sends on a channel at a time. Both rules protect your WhatsApp number. Campaigns run on their own capacity, separate from the inbox, so a large send never slows down your agents' replies.
One campaign per channel
A second campaign on the same channel waits its turn, with the reason "Waiting for the campaign currently sending on this channel". Campaigns on different channels send at the same time. A paused campaign frees its channel, so another campaign can start. To resume the paused one, wait until the other has finished. Until then Resume is disabled.
Automatic protections
You do not need to turn these on.
Trigger | What happens |
|---|---|
More than 1 in 5 messages rejected for rate-limit or quality reasons (at least 50 failures) | Campaign pauses. Successful sends count against failures, so a campaign that recovers keeps going. |
WhatsApp rejects or pauses the template | Campaign pauses. |
Template or channel stops being usable during the send (for example, channel deactivated) | Campaign pauses, with the reason shown. |
The same problem is found before the first message goes out | Campaign fails, with the reason shown. |
Number's quality rating drops to red (Meta only) | Campaigns sending on that number pause. Scheduled campaigns wait and do not start. |
Broadcasting add-on removed | Campaigns pause. |
WhatsApp temporarily refuses a message for rate limits | That message is retried up to 3 times, after 1, 2 and 4 minutes. |
Key limits at a glance
Limit | What it means for you |
|---|---|
WhatsApp only | Instagram and Messenger have no template messages, so they cannot send campaigns. SMS is not included. |
15,000 recipients per campaign | Split larger audiences over several campaigns. A campaign that is too big is refused, never cut short. |
One campaign at a time per number | A second campaign on the same number waits its turn. Campaigns on different numbers send at the same time. |
Duplicates are merged by number, not by person | Someone with two numbers gets two messages. Two overlapping campaigns both send. |
No fallback values | Recipients without a value for a personalisation field are skipped. The preview shows how many. |
WhatsApp's daily tier still applies | We warn you if your audience is larger than your daily limit, but we do not block the campaign. |
Schedule up to 3 months ahead | Pick a date, time and timezone within the next 3 months. |
Not available yet
Dynamic segments, recurring or drip campaigns, A/B tests, carousel and location templates, tracking of link and call button taps, and access through the public API.
CANCELLING
Cancelling stops what is not sent yet. Messages already handed to WhatsApp cannot be recalled. They finish and are reported as sent.