Opt-in is the foundation, not an afterthought
Most guides treat consent as a compliance box near the end. On WhatsApp it belongs at the start, because it is the variable that decides whether the rest of your programme works at all.
The mechanism is worth understanding. WhatsApp gives every recipient a one-tap block and a one-tap report. Those actions feed back into how Meta assesses the quality of your messaging, and message quality is what governs whether your sending limit grows or stays where it is. A list built from contacts who never asked to hear from you does not merely underperform — it constrains the channel's capacity permanently.
So the practical sequence is: earn permission first, then build the campaign.
Sound sources of opt-in, in rough order of quality:
- Someone messages you first. Messages sent from a WhatsApp user to a business are never charged, and a conversation they started is the strongest signal you will get.
- Click-to-WhatsApp advertising. These are a free entry point: a conversation opened this way gives 72 hours in which all messages are free. You get consent and a free window in the same action.
- A checkbox on a form, a checkout, or a booking flow, where WhatsApp is named explicitly rather than bundled into a general "contact me" tick.
- An in-store or on-call ask, recorded against the contact record so you can show when and how it was given.
What does not count: a purchased list, numbers scraped from a directory, or an existing customer database where nobody was asked about WhatsApp specifically. These are the lists that generate blocks.
