WhatsApp does not let you write freely to just anyone. You can only send a free-form message to someone who wrote to you in the last twenty-four hours. After that, the conversation is considered closed, and only an approved template can reopen it.
What it changes, in practice:
- A campaign reaches people who have not written to you. Its first message must therefore always be an approved template, or a scenario that starts with one.
- A scenario that starts with a free-form message can only go out if the contact has just written: a keyword, a first message, a test link. That is why a scenario does not appear in a campaign’s picker if it opens any other way.
- In an ongoing conversation, anything goes: the customer has just written, the window is open, you reply whatever you want.
- A wait block of twenty-four hours or more closes the window. The message that follows in the scenario will be refused, and the console tells you so while you build it rather than when it sends.
Good to know The reflex to adopt: as soon as the message goes to someone who has not just written to you, think approved template. As soon as it answers someone who has just spoken, write freely.