WhatsApp has a very specific rule that can affect how many customer you can reach within a 24-hour period. If you want to send campaigns to large audiences is important to understand how this works so you can prepare your WhatsApp number to be able to reach your entire audience.
Phone numbers with an approved display name can initiate conversations with the following number of unique customers within a 24-hour period:
1,000 unique customers
10,000 unique customers
100,000 unique customers
An unlimited number of unique customers
The value starts at 1,000 unique customers and automatically increases depending on the status and quality rating of your phone number, as well as how often you initiate conversations with unique customers.
How to increase the phone number limit
Every time you start a new conversation with a unique customer, WhatsApp will check if your phone number limit should increase. This is done based on the following criteria:
Your phone number status is Connected.
Your phone number rating is Medium or High.
In the last 7 days, you have started X or more conversations with unique customers, where X is the current message limit divided by two. If you meet these criteria, the message limit will increase by one level in 24 hours
If you have a lower limit than the number of customers you want to reach, follow these tips to try to increase your limit:
Make sure you are sending campaigns to customer who agreed to receive your messages
Make clear the opt-out option, since when customers block your WhatsApp profile or mark it as spam the number rating is affected. However, sending the opt-out command won't affect this rating.
Send relevant and personalized content to your customers. Very generic messages tend to generate more blocks.
It's important to maintain a high sending frequency within the 7-day window for the limit to increase, but avoid sending multiple messages to the same users.
Do not send messages at inappropriate times, for example too late or too early. This can also generate more blocks and spam reports.
Here you can check the full WhatsApp documentation about phone number limits.