Coexistence is the keyword here. You can absolutely use the same number - provided your BSP supports it and you handle the routing properly.
From a technical standpoint, it comes down to choosing the right provider for your scale. If you need a full inbox with shared team access, message templates, and analytics, something like 360dialog or WATI gives you that managed layer. They handle the phone number validation and the meta business verification process, which can be a bottleneck if you're doing it yourself.
But if you're looking for something lean - maybe just a simple API relay without the extra CRM or ticketing overhead - lightweight options like Dualhook work well. My team uses the latter. It keeps costs predictable and doesn't force us into a pre-built inbox when we already have our own stack for routing messages.
A few things to plan ahead for:
Phone number porting - If the number is already registered on the consumer WhatsApp app, you'll need to remove it from the consumer app before migrating to the API. Coexistence lets you avoid that step, but you still need to set up the API correctly.
Webhook architecture - For programmatic builds, make sure whichever BSP you pick provides a reliable webhook with retry logic. Message deduplication is worth setting up early.
Fallback - If you ever need to revert to the consumer app (for testing or backup), most BSPs let you temporarily pause the API session without permanently unlinking the number.
Pick based on whether you want a managed inbox experience or a headless API you can stitch into your own stack. Both work, just different overhead levels.
