When it comes to sending messages, WhatsApp puts a cap on the number of messages that can be sent on a 24-hr rolling period. This is to prevent businesses from spamming their customers/prospects with bulk messages. The number of messages that can be sent depends on the quality rating of the WhatsApp Business Account and the messaging tier that you are in.
The quality rating shows the message quality that your customers have received in the past 24 hrs. There are three different quality states:
Green: High quality
Yellow: Medium quality
Red: Low quality
If your quality reaches a low quality, your WABA status will change as flagged or restricted.
Flagged status occurs when the quality rating reaches a low state. If the message quality improves to a high or medium state and maintains this for seven days, your status will return to Connected. If the quality rating doesn't improve, your status will still return to Connected, but you'll be placed in a lower messaging limit tier.
Restricted status occurs when you reach your messaging limit. During a Restricted phase, you can't send any notification messages until the 24-hour window has been reset. You can still respond to any messages customers initiate.
Messaging Limit Tier
WhatsApp assigns a messaging tier based on the quality rating to a business number which defines the number of unique WhatsApp numbers to whom you can send messages on a rolling 24 hr period. Messaging limits determine how many unique users your business can send messages to on a daily basis.
The messaging limit does NOT limit the number of messages your business can send, just the number of users you are trying to message. It also does NOT apply to messages sent in response to a user-initiated message within a 24-hour period.
In simpler words, you can send any number of messages for 24 hrs to a number which has interacted with your WA business number.
Tier 1: Allows your business to send messages to 1K unique customers in a rolling 24-hour period.
Tier 2: Allows your business to send messages to 10K unique customers in a rolling 24-hour period.
Tier 3: Allows your business to send messages to 100K unique customers in a rolling 24-hour period.
Your business starts in Tier 1 when it registers its phone number.
Best Practices to Improve Quality Ratings
Check if you or anyone from your business has added a template within the last seven days. This may help determine a problematic template(s).
Check that your notifications comply with WhatsApp policies.
Only send messages to users who have opted in to receive messages from your business