The WhatsApp 24-hour window, explained (and how to stop losing it)

This one rule explains most of the confusion people have about WhatsApp for business (it is also one of three Meta rules in our WhatsApp Business API guide): why you can reply to one customer freely and not to another, why templates exist, and why some messages can cost money.

What is the 24-hour window?

The WhatsApp 24-hour window (Meta calls it the customer service window) is the period of 24 hours after a customer's last message to your business. During it you may send any free-form message. When it ends, you can send only an approved template message until the customer writes to you again.

Meta's documentation puts it plainly: template messages are the only type of message that can be sent to a WhatsApp user outside of a customer service window.

Three practical consequences:

• Reply fast. The clock runs from the customer's last message, not from when you saw it.
• A new message from the customer reopens it. Every time they write, you get a fresh 24 hours.
• After it closes, you need a template. That is a pre-approved message, and it can cost money to send. See how template approval works.

Inside the window vs after it closes

A worked example

Priya writes to your business at 10:00 on Monday. You can send free-form messages until 10:00 on Tuesday. If she writes again at 18:00 on Monday, the window now runs until 18:00 on Tuesday. If she says nothing more, then at 10:01 on Tuesday your only option is a template.

Key terms

• Customer service window: the 24 hours after the customer's last message, during which free-form replies are allowed.
• Template message: a pre-approved message you can send outside the window. See how template approval works.
• Free entry point window: a 72-hour period Meta offers for some conversations that start from ads or links, according to Meta's pricing documentation.

How do you know how much time is left?

You should never have to count. In Responseify the shared inbox shows the time remaining right next to the customer's details, so your team can see at a glance which chats can still get a free-form reply. Here is how the inbox works.

What to notice: "24h left" appears with the customer's details. When it runs out, the next message has to be an approved template.

What does the window mean for cost?

Meta decides which messages are charged and at what rate. We do not say that replies inside the window are free or that they are charged: check the rate card in your Meta Business Manager. Marketing templates are charged whenever they are delivered. The full breakdown with rupee examples is in WhatsApp Business API pricing in India.

Tricks that keep conversations inside the window

• Ask a question that invites a reply. A reply restarts the clock, which keeps free-form messaging open.
• Use click-to-WhatsApp ads and QR codes to make customers start the chat, so you begin inside an open window. Meta also runs free entry point windows for some of these; check the current rules.
• Send reminders before the window closes, while you can still write freely.
• Set up auto-replies so a first response goes out instantly, even at night.