Understanding the 24-hour messaging window

Learn how WhatsApp's 24-hour conversation window works, what opens and resets it, and what happens once it expires.

WhatsApp Business API doesn't let businesses message customers freely at any time. This guide explains the 24-hour conversation window — the rule that decides when you can send a free-form message and when you need an approved template instead.

What's covered

What is the 24-hour window?

When a customer sends your business a message, a 24-hour window opens. Inside that window, you can reply normally — with regular text, media, or interactive messages. Once 24 hours pass without a new message from the customer, that window closes and templates become mandatory to reach them again. This keeps messaging customer-led and consent-based, which is core to how WhatsApp's Business API works.

What opens the window

Only a customer action opens the conversation window. This includes:

Sending a direct message — for example, "Hi" or "Price?"
Replying to a template message
Clicking Send message on a Click-to-WhatsApp ad
Using a quick reply or CTA button

Sending a template or a broadcast does not open the window on its own — the customer has to take an action first.

What you can send inside the window

While the window is active, you can send free-form text messages, media such as images, PDFs, and videos, as well as templates, payment links, and order updates. You don't need a template for these messages, and the messaging cost is lower than template-based messaging.

What happens after 24 hours

Once the window expires:

Free-text messages are blocked
Media and interactive messages are blocked
Only template messages are allowed

Sending a template after expiry starts a new, paid business-initiated conversation. If you're picking up a conversation that's gone cold, see how to start a new chat with a customer for the full template-sending flow.

Template categories and pricing

Meta charges for WhatsApp message templates based on their category:

Utility
Marketing
Authentication

Pricing varies by the customer's country. To check the latest template pricing, refer to the DoubleTick conversation cost page. You can also check the pricing applicable to your account directly from your DoubleTick dashboard.

How the timer resets

Every new customer message resets the 24-hour timer. For example:

Customer messages at 10:00 AM → window stays open until 10:00 AM the next day.
Customer replies again at 2:00 PM → the window now extends to 2:00 PM the next day.

This means the window can stay open indefinitely, as long as the customer keeps replying.

Common misunderstandings

A few things customers and new team members often get wrong:

Saving your number doesn't let you message them anytime — it doesn't.
Broadcasts don't open the window — only a customer reply does.
The window isn't permanent — it lasts 24 hours from the customer's last message.
Templates don't open the window automatically — you still need the customer to reply.

Key takeaways

A customer message opens a 24-hour window during which you can send free-form messages.
After the window closes, only approved templates can reach the customer.
Templates are paid and categorized as utility, marketing, or authentication.
Every new customer reply resets the 24-hour timer.
DoubleTick automatically enforces this rule, so you'll always know when a template is required.

FAQs

Does sending a broadcast open the 24-hour window? No. Only a customer action — like a reply or clicking a CTA button — opens the window. Broadcasts alone don't.

Can I still message a customer if I saved their number? No. Saving a customer's number has no effect on WhatsApp's messaging rules. The 24-hour window still applies.

What happens if I try to send a free-form message after the window closes? It will be blocked. You'll need to send an approved template message to restart the conversation.

Does the window last forever once it's open? No, it lasts 24 hours from the customer's last message. Each new reply from the customer resets the timer for another 24 hours.

Are all templates charged the same amount? No. Pricing depends on the template category — utility, marketing, or authentication — and the customer's country.