The 24-Hour Reply Window Explained

Every time a customer sends a message to your WhatsApp Business number, a 24-hour window opens. Inside that window you can reply however you like: plain text, a photo, a document, a quoted reply. Meta calls this the customer service window.

The clock starts from the customer's most recent message, not from the first one. Each new message from them restarts the 24 hours. Your own messages do not restart it, and neither does a campaign you send.

When 24 hours pass without a new message from the customer, the window closes. From then on, WhatsApp only accepts an approved message template from your business until the customer writes again.

WhatsApp is a personal messaging app first. People put up with messages from businesses because they asked for them, or because they are in the middle of a conversation. Meta's rule protects that.

• Inside the window, the customer has just spoken to you, so a free-form answer is expected and welcome.
• Outside it, the business is starting the conversation. Meta wants that first message to be a template it has reviewed, so customers are not flooded with unreviewed promotions.
• Templates carry a category, such as marketing or utility, which is how Meta applies its own rules and charges to business-initiated messages.

Every provider on the official API works under the same rule. A tool that claims to get round it is not using the official channel, and that puts your number at risk.

For how templates are categorised and approved, read How WhatsApp Message Templates Work.

SmartEngage checks the window before it sends anything, so you find out before you type a long reply, not after Meta refuses it. You will see it in three places on the WhatsApp page:

• The customer details panel shows a badge that reads Open for a free reply while the window is open, or Reply window closed once it has passed.
• While the window is open, the normal message box is at the bottom of the thread, with the options to attach a file and quote a message.
• Once it has closed, the message box is replaced by a notice that says when the window closed and that WhatsApp now allows only an approved template, together with a Send a Template button.

If a free-form message is attempted after the window has closed, for example from a screen left open, SmartEngage refuses it rather than passing it to Meta to fail. The message reads "The 24-hour reply window has closed. Use Send a Template in this conversation to reopen it."

When the window has closed, the way back is an approved template. You can send one without leaving the conversation.

• Open the conversation on the WhatsApp page.
• Press Send a Template under the notice at the bottom of the thread.
• Pick one of your approved templates from the list. Each one shows its name, language and a preview of its wording.
• Fill in any values the template needs. SmartEngage pre-fills them with the example values the template was approved with, so check they suit this customer.
• Press Send Template.

The template appears in the thread showing the words the customer actually received. When the customer replies, a fresh 24-hour window opens and the normal message box comes back.

If you have no approved templates, SmartEngage says so and offers a Create a Template button. Meta has to approve a new template before it can be sent, so it is worth having at least one general follow-up template ready before you need it.

While the window is open, the inbox gives you the normal message box and no template option. The Send a Template button only appears once the window has closed, because until then a reply in your own words is all you need. Campaigns are different: every campaign message is an approved template, so a campaign reaches each contact whether or not they have a window open.

A few situations catch people out:

• Sending a campaign does not open a window. Only a message from the customer does.
• A customer reading your message does not open it. They have to send something back.
• Replying yourself does not extend it. If the customer went quiet 23 hours ago, you have about an hour left however many messages you send.

A customer tapping a quick-reply button on one of your templates does count as a message from them, so it opens a new window.

• Check the inbox at least once a day. Most closed windows are simply replies that waited too long.
• Use the Unread tab to see who is waiting on you first.
• When a conversation will need a follow-up later, such as a delivery date or a quote, say so and ask the customer to reply when they are ready. Their reply reopens the window.
• Keep one or two approved follow-up templates for picking conversations back up, so you are never stuck waiting for approval.
• Respect opt-outs. When a customer replies STOP, SmartEngage marks them as opted out and campaigns skip them until they reply START. Do not use a one-to-one template to chase someone who has asked you to stop.

For more on how opt-outs work, read Duplicates, Invalid Numbers and Opt-outs Explained.

The reply window is one of a handful of WhatsApp rules that shape how the inbox works.

For a tour of the whole screen, read How the SmartEngage Inbox Works.

To get a follow-up template ready, see How to Create a Message Template.