When do you need an approved WhatsApp template instead of a normal message?

You need an approved template whenever you are starting the conversation, or continuing one more than 24 hours after the customer's last message. Inside that 24 hour window you can send normal free-form messages.

So the rule in practice:

• Customer messages you, you reply within 24 hours: free-form, no template.
• Customer messages you, you reply 30 hours later: template required.
• You want to message someone who has not contacted you: template required, and

they must have opted in.

Templates are submitted to Meta and reviewed before you can use them. They support variables, so one approved template covers many sends, but the fixed text cannot change per message. Plan the templates you need before you need them: approval is not instant and a pending template is not a fallback you can rely on during an incident.

This is also the answer to the most common WhatsApp automation disappointment. People build a three day nudge sequence, test it inside the window where everything works, then watch it fail in production. Sequences that cross the window need a template at every step that lands outside it.

One design note that saves a lot of trouble: ask for an email address during the first conversation. An email follow-up has no window and no approval queue.