A new business portfolio can deliver messages to a maximum of 250 unique WhatsApp users per 24 hours, outside of a customer service window. See the Messaging Limits document for the full definition.
For example, if you have 10,000 contacts and want to send a template to all of them, you can only reach 250 of them on the first day, another 250 the next day, and so on.
{warning} Adding more WhatsApp numbers does not raise your allowance. Messaging limits are set at the business portfolio level and are shared by every business phone number in that portfolio, so splitting a campaign across several numbers of the same portfolio still hits the same 250 ceiling.
The reliable way to reach more people is to raise the limit itself, by completing Meta business verification or one of the other scaling paths described in the Messaging Limits document.
Until your limit is raised, split your contacts into groups of 250 unique contacts and send to one group per day. This keeps the campaign organized: every contact is messaged exactly once, and nobody is missed.
You can find detailed steps for this method in the Contact Grouping document.