Every WhatsApp reply your team sends falls into one of two buckets: free-form inside the 24-hour window that opens and resets with each customer message, or a pre-approved template once that window closes. From October 1, 2026, Meta bills both — so the decision that matters is which template you’ll need, made before the window closes, not after.
What the 24-hour window actually controls
Meta’s own WhatsApp Business Platform documentation defines the customer service window as the 24-hour period that “opens and resets with each user message.” Inside it, your team can send a free-form reply — no template required. Once 24 hours pass since the customer’s last message, the window closes, and only a pre-approved template message can reach them.
That mechanic hasn’t changed. What has: starting October 1, 2026, every reply sent inside the window — written by a person or by an AI tool — is billed per message at the same rate Meta already charges for template messages, ending the free period for “service messages” that began in November 2024. We covered the billing change in detail here; this guide is about the workflow decision the window forces on your team every day, price aside.
Why the template needs planning, not typing
A template message needs Meta’s approval before you can send it — you cannot write one on the spot once a conversation has gone quiet for a day. Meta’s documentation puts the responsibility on the business to review the category assigned to each approved template and accept the charge that comes with using it.
As a recommended starting point, keep any order-specific reply — a payment confirmation, a delivery date, a slip you’re still checking — inside the same 24-hour window as the customer’s last message. Once a conversation crosses into a new day with no reply from the customer, only an already-approved template reaches them, whatever your team has drafted. The same judgement an AI agent uses to decide when to hand a case to a person applies here too: a question the bot can’t close before the window lapses is one a human should pick up while there’s still time to answer for free.
ตั้งค่าใน 1CS — connect WhatsApp and test your templates
Connect a WhatsApp inbox in 1CS from Settings › Inboxes › New inbox, then choose WhatsApp on the channel screen. 1CS supports embedded signup, the WhatsApp Cloud API, or an existing provider’s credentials — pick whichever matches the WhatsApp Business account your team already has, and add the agents who need to see the conversation.
After connecting, send a message from a test number and reply from 1CS. If that reply needs a template, check the template and its approval status before sending it for real — Meta approves templates on its own schedule, not 1CS’s or yours. The click-by-click steps live in 1CS’s WhatsApp connection guide (Thai only); the channel itself is part of the unified inbox feature.
A template set and checklist to copy
Submit these as utility templates for Meta’s approval before you need them — approval timing is Meta’s call, not yours, so this only works done in advance:
- Order confirmation: “Your order [order number] for [amount] THB is confirmed. Estimated delivery: [date]. Reply here if anything needs to change.”
- Shipping update: “Your order [order number] has shipped via [courier name] with tracking number [tracking number].”
- Payment reminder: “We haven’t received payment for order [order number] yet. Please transfer [amount] THB to [account details] by [date] to keep your order.”
Checklist for whoever replies next:
- Check the timestamp of the customer’s last message.
- Inside 24 hours: reply free-form as usual.
- Past 24 hours: open the approved template list in 1CS and send one of those — don’t attempt a free-form reply, it won’t go through.
- No approved template fits: hold the reply and escalate to a human rather than leaving the customer without an answer.
