What is the 24-hour customer service window on WhatsApp?

Inside the window: free-form session messages

While the window is open you are in what WhatsApp calls a session, and you can send session messages freely. These are non-template messages, so there is nothing to submit for approval and nothing to wait for. You can send plain text, product images, order screenshots, PDFs and invoices, voice notes, location pins, and interactive buttons or lists, all shaped to the exact question the customer asked. This is the natural home of real customer service: answering a query, resolving a complaint, walking someone through a return, confirming a change of address. Because the content is generated in real time by your agent or bot rather than pre-approved, in-window messaging is also the most conversational and the least friction-heavy way to communicate on the platform.

Outside the window: templates take over

Once the window has closed, you can no longer send a free-form message to that customer, because WhatsApp will not deliver non-template content to a contact who has no open session. To reach them again you must send a pre-approved message template in the appropriate category, marketing, utility, or authentication. The template re-establishes contact; if the customer replies to it, a new 24-hour service window opens and you are back to free-form messaging. This is why teams that handle delayed or asynchronous support lean on well-designed utility templates: an order-update or appointment-reminder template can legitimately reopen a conversation and give the customer a reason to respond, which in turn reopens the free window for the rest of the exchange.

• No open session means free-form messages will not deliver
• Use an approved template to re-establish contact
• A customer reply to your template opens a fresh 24-hour window
• Choose the correct category: marketing, utility, or authentication

What the window means for your WhatsApp costs

A common misconception is that the 24-hour window is a billing unit. It is not. Since 1 July 2025, Meta bills per delivered message priced by category, marketing, utility, or authentication, rather than by conversation. The service window is a free-messaging privilege layered on top of that: while a session is open, your free-form service replies to the customer are the cheapest way to communicate, because you are not paying template-category rates for routine back-and-forth support. The practical takeaway is that responsiveness is not just good service, it is good economics. Answering quickly keeps conversations inside the free window and reduces how often you need to pay to send a template to reopen contact. On InfiQ you always see transparent rupee pricing (ex-GST), so you can see exactly what each category costs and plan your messaging mix accordingly.

Practical tips to make the most of the window

Most of the value in the 24-hour window comes from operational discipline rather than clever tooling. Fast first-response times keep sessions open; clear routing means a customer's message reaches an agent before the clock runs down; and thoughtful template design gives you a reliable way to reopen contact when a conversation genuinely stalls. Teams that treat the window as a design constraint, rather than a rule they trip over, tend to spend less on templates and resolve more tickets in a single continuous thread.

• Prioritise fast first responses to stay inside the free window
• Route inbound messages so they reach an agent before 24 hours pass
• Keep a small library of clean utility templates ready to reopen stalled chats
• Use quick replies and saved answers to speed up in-window service
• Track how often conversations expire, it signals where response times slip