The WhatsApp 24-hour customer service window, explained
The WhatsApp 24-hour customer service window is the period after a customer's last message during which a business can send free-text replies. Once it closes, only pre-approved templates can be sent. Any new message from the customer resets the clock, which matters directly for how drip sequences and delayed follow-ups must be built.
- Inside the 24-hour window, replies can be free-text — no template or Meta approval needed.
- Outside the window, only approved templates can reach the customer, whatever the message content.
- Any inbound message from the customer, even a single word, resets the 24-hour clock.
- A Wait / Delay step longer than 24 hours in a flow must switch to a template, not a session message.
- Certain entry points, like clicking an ad or messaging first, can open a fresh window even for a returning customer.
The core definition
The 24-hour customer service window is the period starting from a customer's most recent message during which a business can send ordinary, free-text replies on WhatsApp. Once 24 hours pass without a new message from the customer, that window closes, and the business can no longer send plain text. Only a pre-approved template message can reach them.
This rule exists to protect WhatsApp users from being messaged indefinitely by businesses they contacted once. A customer who messages your store to ask about stock availability is opting into a live conversation for the next 24 hours, not a standing invitation for you to message them whenever you choose afterwards.
It applies identically whether the conversation is handled by a human agent in a live-chat inbox or by an AI agent replying automatically: the window is a WhatsApp platform rule, not something that varies by who or what is typing the reply.
It's worth being clear about what the window does not restrict: it has no bearing on how many messages you can send inside it, and it doesn't stop a customer from messaging you at 2 AM and expecting a reply at a reasonable hour instead. It governs whether a reply can be free-form text or must be a pre-approved template. On cost, replies inside the window are free of Meta charges only until 30 September 2026; from 1 October 2026 Meta charges them per message at the utility rate after 1,000 free service messages per number per month, as explained in WhatsApp Business API pricing in India.
Session messages vs template messages
| Session message | Template message | |
|---|---|---|
| When usable | Inside the 24-hour window only | Anytime, window open or closed |
| Approval needed | None | Pre-approved by Meta |
| Content | Free text, any wording | Fixed structure with variables |
| Typical use | Live conversation, answering questions | Reminders, notifications, re-engagement |
This is why a chatbot answering a live question can reply freely, while an order-shipped notification days later must be a template. It's also why businesses that only ever send templates, without engaging in live session replies, tend to feel less conversational to customers. The free-text window is what makes WhatsApp automation feel like a real conversation rather than a string of one-way alerts.
What resets the window
Any inbound message from the customer resets the 24-hour clock, restarting the countdown from that new message's timestamp. This means an active back-and-forth conversation stays inside the window indefinitely, while a customer who goes quiet moves the business back to template-only messaging after 24 hours from their last reply.
Automated replies the business sends do not reset the window; only messages from the customer do. This includes very short replies too: a customer typing just 'ok' or a single emoji still counts as a message and restarts the full 24-hour countdown, even though it carries almost no new information.
Why this matters for drip sequences
A drip sequence spanning several days (a lead-nurture sequence, an abandoned-cart follow-up) will almost always fall outside the 24-hour window for later messages, since the customer hasn't necessarily replied recently. This means later steps in the sequence need to be Utility or Marketing templates, submitted and approved in advance, rather than assuming free-text will work throughout.
On Convo360, a Wait / Delay block set to minutes, hours or days is built specifically to persist across this gap, and the flow should branch to a template send once the delay exceeds the live window. A common pattern is to send the first follow-up as a session message if it lands within a couple of hours of the customer's last reply, then switch every subsequent step in the same drip to a template, since there's no guarantee the customer will have said anything in between.
Getting this wrong is one of the most common reasons a drip sequence silently stops delivering: the flow tries to send a session message outside the window, it fails, and without checking Flow Logs the business may not notice for days.
Free entry points that open a window
Certain interactions can open or reopen a customer service window even without a fresh text message. For example, a customer tapping a Click to WhatsApp Ad or certain in-app entry points count as the customer initiating contact. Meta's own documentation covers the current list of qualifying entry points; see developers.facebook.com for the authoritative detail, since specifics can be updated by Meta over time.
These entry points matter for campaign planning: a business running Click to WhatsApp Ads can often follow up with a free-text session reply the moment someone clicks through, rather than needing an approved template for that very first response, because the click itself is treated as the customer initiating contact.
How Convo360 handles this automatically
Flow Builder's Send Message block (session) and Send Template block (approved template) are kept distinct, and a Condition checking the last-inbound timestamp can route a flow to the right one automatically, so you don't have to track windows manually per contact. See /docs/whatsapp/ and /docs/templates/.
This also shows up in Flow Logs, which note when a session send would have failed outside the window and was routed to a template instead, giving you visibility into how often that fallback triggers, which is useful for deciding whether a flow's timing needs adjusting.
The same principle covers live-chat handoff: when a human team member takes over a conversation from the team inbox, the window that applies is still the same 24-hour customer-service window tied to the customer's last message, not a separate clock for human-handled chats. A support agent replying to a customer who wrote in eighteen hours ago still has six hours of free-text room before needing to fall back on a template.
Example conversation
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Frequently asked questions
What happens if I send a free-text reply after the window closes?
It will fail to deliver. WhatsApp only permits approved template messages once the 24-hour window has closed, regardless of message content or urgency, so plan ahead for anything you may need to send later.
Does a customer opening a chat without replying reset the window?
No, only sending an actual message resets the window. Simply reading or opening the conversation on the customer's side has no effect on the timer.
Can I send multiple messages within the 24-hour window?
Yes, as many free-text session messages as needed can be sent while the window remains open, with no per-message template approval required, though from 1 October 2026 many of them count as billable service messages.
Is the 24-hour window the same for every business?
Yes, this is a platform-wide WhatsApp policy that applies uniformly, not something that varies by business size, industry, connecting platform or whether a human or an AI agent is replying.
Do template messages also count within the window?
Templates can be sent at any time, including inside the window, though most businesses use free-text replies then since it's more natural for live conversation.
Related reading
Available across India — see WhatsApp & AI calling automation by state and city.