The 24-hour window
Why Flyby sometimes won't let you reply to a customer on WhatsApp, Messenger or Instagram, and what the banners above the reply box mean.
Meta (the company behind WhatsApp, Messenger and Instagram) has a rule: a business can reply freely within 24 hours of the customer's last message. After that, messaging is restricted. Flyby follows this rule so your messages aren't rejected and your number or Page stays in good standing.
Meta channels only
Website chat has no window. You can reply there anytime.
How the window works
The clock starts from the customer's last message, not your last reply. Every new message from the customer opens a fresh 24-hour window.
| Time since the customer's last message | Messenger & Instagram | |
|---|---|---|
| Under 24 hours | Reply normally (AI and team) | Reply normally (AI and team) |
| 24 hours to 7 days | Closed: you can't reply | Only your team can reply, sent with the Human Agent tag |
| Over 7 days | Closed | Closed |
The AI agent only replies inside the first 24 hours, which is natural: it's always answering a message that just arrived.
When the reply box is locked
When Flyby can't send, the reply box turns grey and its placeholder tells you why. A ? inside it opens this page.
After 24 hours:
More than 24 hours since their last message. WhatsApp only allows approved template messages now.
Flyby doesn't send template messages yet, so replying works again as soon as the customer sends a new message.
Waiting for an answer to a comment DM
When a conversation started from a comment reply, Meta allows only that one DM until the person answers. The box stays locked with "Waiting for … to answer the DM about their comment" and unlocks as soon as they write back.
Replying from the Instagram or Messenger app
Meta's 24-hour limit applies to apps like Flyby, not to a person replying in the Instagram app, the Messenger app or Meta Business Suite. When the box is locked, you can still answer from your phone.
Those replies show up in the Flyby conversation too, marked "Sent from the Instagram app" (or Messenger), and the AI agent stops replying in that conversation, the same as when you reply from Flyby.
Internal notes always work
Even when the box is locked for replies you can switch to Internal note, because notes are never sent to the customer.
When a message isn't delivered
If you try to send and Meta refuses, the message is not saved in the conversation, your text goes back into the reply box so you don't lose it, and a message tells you why:
| Message | What it means | What to do |
|---|---|---|
| Not sent: the 24-hour window is closed | The allowed time has passed | Wait for the customer to write, or reply from the app on your phone |
| Meta refused: your Meta app isn't approved for Human Agent | Replies after 24 hours need Human Agent approval | Reply from the Instagram / Messenger app on your phone, or get Human Agent approved and click Re-check |
| Not sent: this channel is disconnected. Check Settings | The channel is turned off or not connected properly | Check it in Settings → Channels & integrations |
| Not sent: no platform ID for this customer | Flyby can't find the customer's account on that platform | Reach the customer on another channel |
| Meta test number: add this customer's number to the allowed list in your Meta app | WhatsApp is connected with Meta's test number, which only replies to listed numbers | Add the number in WhatsApp → API Setup → To, or connect your real number (WhatsApp) |
| Meta couldn't deliver this message | Meta refused for another reason | Try again shortly; if it keeps happening, check the channel settings |
Under any message that didn't go through (for example an AI reply Meta refused) you'll see Not delivered or Not sent: the 24-hour window is closed in red.
The customer didn't come back?
- Reach them outside Flyby. From the lead page or contact profile, tap their number to call, or the WhatsApp button to open a chat from your phone.
- Log what happened. After the call, use Log call in the lead's activity, and add a follow-up task if you need to get back to them.
- Close the conversation if it's done. If the customer writes again it reopens on its own.
Replying yourself from the Instagram or Messenger app is fine. Don't try to get around the rule any other way (other tools, bulk messages): Meta can restrict or disable accounts with repeated rejected messages. Read the Meta messaging policy.