The WhatsApp 24-hour window: how it works and how to reopen it

The WhatsApp 24-hour window is the period in which a business can reply to a customer with free-form text, without prior approval. It opens when the customer sends a message to your number and restarts with every new message from them. Outside the window, only a template approved by Meta goes out — and that distinction sets both what you can write and what you pay.

What opens the window

Exactly one thing: a message from the customer to your number. These do not open it:

• the customer reading your message;
• the customer tapping a URL button inside your template;
• the customer saving your contact;
• a purchase, a sign-up or any event outside WhatsApp.

A quick reply button, unlike a URL button, produces a message from the customer — and that one does open the window. It is the difference that makes quick reply buttons worth more than they look.

What goes out inside the window

Practically everything, with no approval: free-form text, images, documents, audio, video, location, contacts, reactions, buttons and interactive lists. This is the support situation, and Meta does not charge for these messages.

What goes out outside the window

Only an approved template, with variables filled in at send time. This is the notification situation — the business starting the conversation — and it is what Meta charges for, priced by category.

Trying to send free-form text outside the window returns an error. It is not the provider refusing: it is Meta, and no provider works around it.

The question that resolves 90% of sending errors is: who spoke last? If it was the customer, within 24 hours, write whatever you like. If it was you, it is a template.

How the window is counted

• The clock starts at the last message received from the customer, not the first.
• Each new message from them resets it to a full 24 hours.
• The window is per customer number, not per conversation or per agent.
• It does not pause outside business hours or at weekends.

In practice: a customer who writes at 6pm on Friday can only receive free-form text until 6pm on Saturday. Support resumed on Monday starts with a template.

How to reopen a conversation

There is exactly one route, and it has a cost:

1. Send an approved template, in the category that matches the real reason for contact.
2. If the customer replies, the window reopens and you are back to free-form text.
3. If they do not reply, you are still outside the window — and sending another template does not change that.

This is why a template with a quick reply button is more useful than a purely informative one when you need the conversation to continue: the tap produces a customer message, and the window opens.

The most common beginner mistake

The system tries to send free-form text to a customer who never wrote in — because the trigger came from the store, not from WhatsApp. A paid order, a sign-up, an abandoned cart: none of them opens a window.

Every notification triggered by an event in your own system is, by definition, a message outside the window. Which means: template, always.

How this shapes support design

• Reply fast — inside the window it is free and unrestricted; after it, it is a billed template.
• Close the topic within 24 hours — leaving something open until tomorrow costs a template.
• Use quick reply buttons — when you need the conversation to continue, give the customer a cheap way to answer.
• Do not build flows that depend on a reply — if nobody answers, the flow stalls outside the window.

How this combines with template categories and price is in WhatsApp API pricing.

Frequently asked questions

Does the 24-hour window apply to every message?

It applies to messages the business sends. Receiving customer messages is always possible — the window restricts what you send, not what arrives.

Can I send a template inside the window?

You can, and it is billed normally. Inside the window it rarely makes sense: free-form text does the same job at no cost.

Does the window restart when the customer reads my message?

No. Only a message sent by them restarts the clock — reads, link taps and saving your contact do not count.

Is there a longer window for customer service?

The general rule is 24 hours. Specific programmes and situations have their own conditions, but any integration should be designed assuming the 24 hours.