Every business sending on the official WhatsApp Cloud API runs into the same rule, usually the hard way: once a customer messages you, you have a 24-hour window in which you can reply with anything — text, images, documents, a straight answer to their question. Once that window closes, free-form replies are rejected. You can only re-open the conversation with a template Meta has already approved.
Why the rule exists
WhatsApp is a private channel. The window is Meta’s way of making sure businesses answer conversations customers started, rather than using an inbound message as a licence to market indefinitely. It is a reasonable rule. It is also the single most common reason a campaign that looked successful quietly stops converting.
Where teams lose money
The failure is rarely the send. It is the gap between a customer replying and somebody noticing. A blast goes out on Friday afternoon, replies arrive over the weekend, and by Monday morning a third of them are outside the window. Those conversations are not lost, but re-opening them now costs a template and reads as a marketing message rather than an answer.
The expensive part of a WhatsApp campaign is not the send. It is the reply you did not get to in time.
What to do about it
- Make the window visible. If your team cannot see how long is left on a conversation, they cannot prioritise it. GSendr shows the countdown on the thread itself.
- Route replies to a shared inbox, not a phone. One person’s handset is a single point of failure. A shared desk means whoever is free answers.
- Send when you can staff the reply. A Tuesday morning send with three people on the desk will out-earn a Friday evening send every time.
- Get your re-open templates approved early. When a window does close, you want the template already sitting there approved, not entering review.
The practical version
Treat a campaign as staffed work, not a broadcast. Decide before you send who is answering, for how long, and what happens to conversations nobody reached. The channel rewards teams that plan the second half of the conversation as carefully as the first.