Meta quietly shut off three Messenger message tags many order-update tools relied on to text customers after the 24-hour reply window closes. Requests using POST_PURCHASE_UPDATE, CONFIRMED_EVENT_UPDATE or ACCOUNT_UPDATE have returned error code 100 since April 27, 2026 — and the two things that still work after that window need a different setup than most Thai Pages have running today.
What actually opens and closes Messenger’s 24-hour window
Messenger’s standard messaging window isn’t tied only to the last message a customer sent — it resets on any of six actions Meta lists in its own Messenger Platform policy: a message to the Page, a tap on a call-to-action button such as “Get Started,” starting a thread from a Click-to-Messenger ad, opening a conversation through a Send-to-Messenger or Checkbox plugin, clicking an m.me link with a ref parameter on an existing thread, or reacting to any message. Inside that window a Page can send whatever it needs. The problem for a chat-commerce order is that a courier delay rarely waits for the customer to do one of those six things again before your team needs to speak up.
The tags that covered the gap just stopped working
Until recently, three message tags let a Page message a customer outside that window for specific purposes: POST_PURCHASE_UPDATE for a recent order, CONFIRMED_EVENT_UPDATE for a booking reminder, and ACCOUNT_UPDATE for a change to the customer’s own account. Meta’s own Messenger Platform changelog, March 27, 2026, confirms all three stop working from April 27, 2026: any Send API request using one now returns error code 100, because “deprecated message tags are no longer allowed in API requests.” Meta’s recommended replacement, Utility Templates, is pre-approved messaging its 2025 developer blog post lists as live for Thailand, the Philippines, the US and Vietnam — but it needs a template-submission process most small Pages haven’t started. What still works with no setup is the HUMAN_AGENT tag: the same policy page describes it as letting a Page “manually respond to user messages within a 7-day period” — a real person typing a reply, not an automated broadcast.
Set up in 1CS
1CS’s Messenger connection doesn’t implement message tags at all. Once the 24-hour window closes, the reply box on that conversation shows a restriction message — “การจำกัดหน้าต่างข้อความ 24 ชั่วโมง,” the 24-hour message window limit — the same wall Meta puts on the Page’s own inbox, with no tag to send around it. So the fix has to happen before the window closes. Build an Automation rule (AI > เงื่อนไขอัตโนมัติ) with the trigger “ข้อความถูกสร้าง” or “การสนทนาไม่มีการตอบสนอง” (idle conversation), a condition on your order or COD label, and an action that adds a label like “reply before 24h” and assigns it to a teammate — so a delayed parcel gets flagged while there’s still time to answer. This sits inside 1CS’s AI Agent tools; the Thai help center covers the same screens in Connect a Messenger inbox and สร้างกฎอัตโนมัติ. If the window has already closed and nobody can reply as a genuine Human Agent case, use a channel built for this instead — 1CS’s unified inbox also connects WhatsApp, whose own pre-approved templates exist for exactly this kind of outside-window update, as covered in WhatsApp’s own 24-hour window — rather than let the customer think the shop went quiet.
A status line to send before the window closes
As a recommended default, not a platform requirement: flag any order nearing 24 hours since the customer’s last Messenger action, and send the update before the clock runs out rather than after.
Hi [customer name], your order [order number] is still with [courier name] — last scan was [status/date]. We’re keeping an eye on it and will update you again by [time/date] even if nothing’s changed by then.
A short checklist for whoever’s on shift: confirm the order actually needs an update, not just a routine scan; send the line above before 24 hours is up; if it’s already closed, check whether a teammate can still answer as a Human Agent case, or move the conversation to LINE or WhatsApp; and never promise a delivery date the courier hasn’t given — see when a delay message needs a second, harder deadline.
