> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chatsyncs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# The 24-Hour Customer Service Window

> The 24-hour customer service window in the WhatsApp Cloud API — what it is, how the rolling timer works, what you can send inside vs outside the window, and how to reach a customer when the window is closed. Use when a customer asks why their message failed after 24 hours, why they can only send templates to some users, or how the WhatsApp messaging window works.

The 24-hour customer service window is a Meta rule that controls when a WhatsApp Business
number can send free-form messages. It opens the moment a customer sends a message and stays
open for 24 hours. Outside this window, only pre-approved templates can be sent. The rule
exists to prevent businesses from spamming users.

## How the window works

When a customer sends **any** message to your WhatsApp Business number, a 24-hour window
opens. During this window you can send text, images, documents, video, audio, stickers — any
message type. After 24 hours with no new message from the customer, the window closes.

## The window is rolling (resets with each message)

The 24-hour timer resets every time the **customer** sends a new message.

**Example:**

* Customer sends "hi" at **10:00 AM** → window open until **10:00 AM next day**
* Customer sends "hello" again at **2:00 PM** → window resets, now open until **2:00 PM next day**
* The window does NOT close at the original 10:00 AM — it follows the most recent customer message.

## Outside the window — templates only

When the window is closed (no customer message in the last 24 hours), you can only send
**Meta-approved message templates**. Free-form text, images, and other message types will
fail. Templates must be created and submitted to Meta for approval before use. See
[Why templates exist](/meta-api/templates/why-templates-exist).

## Reopening the window

If you send a template and the customer **replies** (any reply — even "yes" or "no"), the
24-hour window reopens and you can send free-form messages again.

## Reference image

<Frame caption="A WhatsApp template message sent outside the 24-hour window, prompting the customer to reply.">
  <img src="https://mintcdn.com/chatsyncs/9KTO5p9xBuKseWPL/images/meta-api/messaging/24-hour-customer-service-window/template-message-example.png?fit=max&auto=format&n=9KTO5p9xBuKseWPL&q=85&s=4d1f3146911ee482c0c7fb1972a6d5c8" alt="Template message example" width="1024" height="863" data-path="images/meta-api/messaging/24-hour-customer-service-window/template-message-example.png" />
</Frame>

## Frequently asked

<AccordionGroup>
  <Accordion title="Why can't I send a message to a customer I messaged yesterday?">
    The 24-hour customer service window has closed. Your customer hasn't sent you a message in
    the last 24 hours. You can only send a pre-approved template message to re-engage them.
  </Accordion>

  <Accordion title="What is the 24-hour window in WhatsApp?">
    When a customer messages your WhatsApp Business number, a 24-hour window opens during which
    you can send any message type. After 24 hours of silence from the customer, the window
    closes and only approved templates can be sent.
  </Accordion>

  <Accordion title="Does the 24-hour timer reset if the customer messages again?">
    Yes. The window is rolling — it resets to 24 hours from the customer's most recent message.
    If they message at 10 AM and again at 2 PM, the window is open until 2 PM the next day, not
    10 AM.
  </Accordion>

  <Accordion title="How do I message a customer when the window is closed?">
    Send an approved template message. If the customer replies to it, the window reopens and
    you can send normal messages again.
  </Accordion>

  <Accordion title="Why does WhatsApp have this 24-hour rule?">
    To prevent businesses from spamming users. The rule ensures businesses can only send
    free-form messages in response to a customer-initiated conversation.
  </Accordion>
</AccordionGroup>

## Gotchas & common mistakes

<Warning>
  * **Sending free-form text outside the window** — results in a failed message error. Always
    check whether the window is open before sending non-template messages.
  * **Thinking the window is fixed** — the window resets with every customer message.
  * **Sending a template and not waiting for a reply** — the window only reopens when the
    customer replies. Sending another template without a reply does not reopen it.
  * **Confusing the 24-hour window with template approval** — templates must be created and
    approved by Meta in advance. See [Why templates exist](/meta-api/templates/why-templates-exist).
</Warning>