# The WhatsApp 24-hour window, explained for developers

The 24-hour window, which Meta calls the customer service window, is the period during which a business may answer a customer in free text. It opens when the customer writes and lasts 24 hours; each new message from the customer restarts it. Outside it, only an approved template can be sent.

## The rule

| Situation | What you may send |
| --- | --- |
| The customer wrote less than 24 hours ago | Free text, buttons, lists, media, a Flow; and templates |
| The customer wrote more than 24 hours ago | An approved template only |
| The customer never wrote | An approved template only |

## What reopens it, and what does not

- A message from the customer reopens the window for 24 hours.
- A template you send does **not** reopen it. Only the customer's answer does.
- A message written from the WhatsApp Business app, in [coexistence](https://nodium.io/en/features/coexistence), does not reopen it either.

## Read it before you send

With Nodium, every conversation carries `window`: `open`, `expiresAt` and `minutesLeft`, and `message.received` carries `window_expires_at`. Free text outside the window is refused before it reaches Meta, with `window_closed` (409): a message never looks sent when it was not.

```ts
const conversation = await nodium.conversations.get(conversationId)

if (conversation.window.open) {
  // Inside the window: free text, buttons, lists
  await nodium.messages.send({ channelId, to, type: 'text', text: 'Your order has shipped.' })
} else {
  // Outside: only an approved template goes through
  await nodium.messages.send({ channelId, to, type: 'template', templateName: 'order_shipped', variables: { 1: 'Karim' } })
}
```

## What it changes on the bill

Meta bills templates per message, and counts free-text replies as service messages, with a monthly free allowance per number. See [Meta's pricing explained](https://nodium.io/en/guides/meta-pricing).

## Frequently asked questions

### Can I extend the 24-hour window?

No. Only a new message from the customer restarts it. To write after it closed, send an approved template.

### Does a button tap from the customer count?

Any message the customer sends, a button reply included, opens or restarts the window.

## Sources

- [Meta — WhatsApp Business Platform pricing](https://developers.facebook.com/docs/whatsapp/pricing)

Updated 2026-11-10 · https://nodium.io/en/guides/24-hour-window