The customer service window

When you can send a normal message, when you need a template, and why you do not have to keep track of it.

WhatsApp does not let businesses message people whenever they like. Whether you can send a normal message, or have to send a pre-approved template, comes down to one thing: whether a customer service window is open on that conversation.

This applies to every way of using the Inbox — the hosted inbox, the API, the MCP server and your own front end all follow the same rule, because it is WhatsApp's rule, not ours.

How it works

When a customer messages you, a timer starts. While it is running, you can send anything: text, images, documents, voice notes. Every new message from the customer resets it.

When it runs out, the window is closed. WhatsApp will no longer accept free-form messages to that person, only an approved template. Sending a template the customer receives opens a new window, and from that point you can reply freely again.

How long the window lasts

How the conversation started	Window
The customer messaged or called you	24 hours, reset each time they message again
The customer arrived from an Ad that Clicks to WhatsApp, or a Message button on a Facebook or Instagram Page	7 days
The customer has never messaged you	No window — a template is the only way to reach them

What you can send

Window	What you can send
Open	Anything — text, images, documents, audio, video, location
Closed	An approved template only

We keep track of it for you

This is one of the things the Inbox takes off your hands. Every inbound message, every reset and every expiry is tracked per conversation. You never calculate a deadline yourself, and you cannot accidentally send a message that WhatsApp is going to reject.

In the hosted inbox you can see the state in the chat itself. A conversation with an open window has the normal message box. A conversation whose window has closed says so, and offers your approved templates in place of free typing — so the answer to can I just reply to this one? is always on the screen in front of you.

Why it matters beyond replying

The window is also what decides whether a conversation is free or billed. Conversations started from an Ad that Clicks to WhatsApp or a Page Message button are free entry point conversations and are not charged inside their window. See Free vs Billed Messaging.

Further reading

• Meta's Service messages documentation — the full rules, including which message types count as service messages

• Templates — what Meta allows in template content, and how approval works