What is the WhatsApp session window?
The WhatsApp session window is the 24-hour period that starts when a customer messages your business, during which the business can reply with free-form content instead of a pre-approved template.
When the window opens.
The window opens the moment a customer sends your business a WhatsApp message. From that point you have 24 hours to reply with whatever you like: plain text, images, PDFs, voice notes, buttons. Every new inbound message from that customer resets the clock to a full 24 hours again. The window is tracked per customer, not per topic, so a long back and forth thread all sits inside one rolling window.
What you can send inside it.
Inside the window your replies are free-form. Nothing needs advance approval from Meta, so a human agent or an AI agent can answer in natural language, ask a follow-up question, or attach a quotation. This is where almost all real customer service happens. Businesses that reply quickly rarely bump into the edge of the window at all, because each customer reply extends it by another 24 hours.
What happens after 24 hours.
Once 24 hours pass with no new message from the customer, the window closes. Your business can still start a fresh conversation, but only with a pre-approved template message, and only if the customer has opted in. The customer's reply to that template opens a new 24-hour window. That is the whole rule: customer-led conversations are open, business-led conversations are templated.
The Voltade take
We design WhatsApp agents to answer fast enough that most conversations never leave the window, and to fall back to an approved template when a thread has gone quiet. Which side of the 24-hour line a conversation sits on is the single biggest driver of what WhatsApp costs you, so we build flows around it rather than around it happening by accident.
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SMEs are eligible for up to 50% Productivity Solutions Grant (PSG) support for the adoption of Voltade AI solutions, a Pre-Approved Solution under the IMDA SMEs Go Digital programme.