The WhatsApp 24-hour service window explained (and how to use it)
What the 24-hour customer service window is, why it exists, when free-form replies are allowed, and how to design flows that make the most of it.
The 24-hour service window is the most important rule in WhatsApp Business messaging — and misunderstanding it is the source of most 'why can't I reply?' confusion. Here's what it is, why it exists, and how to design your support and automation around it.
What the window is
When a customer messages your business first, a 24-hour window opens during which you can reply with free-form text at no marketing-template cost. After 24 hours since their last message, you can only re-engage using an approved template. The rule exists to keep WhatsApp spam-free — businesses can't message people unprompted, but they can have a real conversation once the customer initiates.
Why it's your superpower
Inside the window, replies are free-form and cheap. This is where the highest-value conversations happen — support, lead qualification, sales. Design your welcome bots and support flows to maximise the window: capture what you need while it's open, resolve fast, and use a utility template to re-open dormant conversations if needed. Read our support best practices guide for the full flow design.
Re-engaging after the window closes
Once the window closes, you need a template. A 'is your issue resolved?' utility template is worth having approved for exactly this — it re-opens the conversation when a support thread goes cold. For marketing re-engagement, use an approved marketing template (and accept the per-message cost).
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