Once you complete the WhatsApp approval and onboarding process, your Twilio phone number will be enabled for WhatsApp. For these approved and enabled customers, WhatsApp has imposed rate limiting when ramping up your Twilio WhatsApp messaging application.
Due to these rate limits, Twilio recommends customers intending to initiate more than 1000 conversations with unique customers to gradually roll out their WhatsApp launch over the course of a week. In this context, a customer is a unique WhatsApp end user phone number.
Note: Users who sign-up for WhatsApp using Self Sign-Up may experience a lower limit initially until Meta Business Verification is completed. For more information on those limits and how to complete verification see our Self Sign-Up Overview and FAQ.
Note: If you are seeing an API response with error 63018 and message 'Account <SID>' exceeded the 1 rps rate limit' when sending multiple WhatsApp Messages at once, please ensure you are not still using the Twilio Sandbox number (whatsapp:+14155238886) to send your messages. There is a limit of one request every 3 seconds with the Sandbox number at this time, and should only be used for testing out your integration or the WhatsApp Business API features in general. Learn more here: Twilio WhatsApp Sandbox Limitations.
WhatsApp rate limits
Here are the four messaging limit levels:
- 1K business-initiated conversations with unique customers in a rolling 24-hour period.
- 10K business-initiated conversations with unique customers in a rolling 24-hour period.
- 100K business-initiated conversations with unique customers in a rolling 24-hour period.
- An unlimited number of business-initiated conversations in a rolling 24-hour period.
Every new WhatsApp-enabled Sender is initialized as being allowed 1000 business-initiated conversations with unique customers in a rolling 24-hour period. If the Sender reaches the messaging limit, more conversations can be started as soon as one or more active conversation ends.
WhatsApp monitors message volume as well as quality (see below), and will automatically move customers between tiers based on the total number of unique business conversations across the past 7 days.
If, within the past 7 days, a WhatsApp Sender has initiated business conversations with half the unique customers of the per day limit, and maintains a good "quality rating" from WhatsApp, that Sender will automatically be moved to the next tier 24 hours later.
Please note, a Sender may be prevented from moving to the next rate tier, or even moved down a tier, if WhatsApp's internal "quality rating" for the number is low. Twilio is not able to influence this rating or surface it to customers in Console. See "Quality rating" below for more details.
If you exceed the limit for your tier, your messages will be undelivered with error 63018.
Notice: Twilio is unable to manually move or request that customers be moved between rate limit tiers. In addition, WhatsApp will not start a number on a higher tier or manually increase the limit at this time.
Example 1: A Twilio WhatsApp Sender begins by being able to initiate business conversations to 1000 unique customers per day. On day 1, the Sender starts 500 business conversations to unique customers by 3pm. The message limit for the Sender is raised to 10,000 unique customers by day 2 at 3pm.
Example 2: A Twilio WhatsApp Sender begins by being able to initiate business conversations to 1000 unique customers per day. On day 1, the Sender starts 100 business conversations to unique customers. On day 2, the Sender starts another 300 business conversations to unique customers. On day 3, the Sender starts another 100 business conversations to unique customers by 3pm. This brings the total number of unique business conversations in the last 7 days to 500. The message limit for the Sender is raised to 10,000 unique customers by day 4 at 3pm.
This rate limiting does NOT apply to messages sent in response to a user-initiated message within a 24-hour period.
Because WhatsApp encrypts messages, it relies on user feedback to measure quality of messages. WhatsApp uses this feedback to track an internal "quality rating" for senders that can effect how users are able to move between rate limiting tiers. Factors including the frequency rate of "report spam" and "block" on your sender may influence the quality rating." Senders with the Low quality rating may not be eligible to move up in rate limiting tiers.
In order to maintain high quality, WhatsApp recommends the following:
- Make sure messages follow the WhatsApp Business Policy.
- Only send messages to users who have opted into receiving messages from your business.
- Make the messages highly personalized and useful to users. Avoid sending open-ended welcome or introductory messages.
- Be mindful of messaging frequency; avoid sending customers too many messages a day. Be thoughtful of informational messages, optimizing for content and length.
A low Quality rating can result in a number being prevented from moving to a higher rate tier, or even in some cases being downgraded to a lower rate tier.
For more details, see Capacity and Messaging Limits (developers.facebook.com).
Notice: Twilio is unable to change or request customer quality rating changes. We are also unable to show your number's rate tier or quality rating in the Twilio Console. The only way to keep your quality high is to follow WhatsApp's recommendations.