HeroChat Blog

WhatsApp's 24-hour window: what it is and how to respect it

What the 24-hour window is

On the official WhatsApp Business API, once a customer messages you, you have 24 hours to reply freely with any type of message. After those 24 hours pass without the customer writing again, you can no longer send regular messages — only pre-approved templates from Meta.

Why this rule exists

It's an anti-spam measure from Meta: it stops businesses from bombarding users with messages outside an active conversation. It makes sense from a user-experience standpoint, but it does change how you need to plan your remarketing.

How to keep contacting a customer after the window closes

• Pre-approved message templates: Meta allows sending messages outside the window only if they use a format approved in advance (e.g. appointment reminder, shipping notification).
• Design remarketing within the window: most follow-up sequences (2h, 24h, 48h) fit within or right at the edge of the window, if the customer replied something in between.
• Don't rely 100% on free-form messages for everything: if your business needs to contact customers after days of inactivity, you need approved templates set up in advance.

How HeroChat solves this

HeroChat designs remarketing sequences with the 24-hour window in mind, and flags when a message would need an approved template instead of a free-form one — so you don't lose contact with a customer over a technical rule you didn't know about.

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