Standard messaging window

The 24-hour rule

ActiveStill in effect, unchanged in 2026

In short

The 24-hour rule (Standard messaging window) is the period in which a Facebook Page can message a customer on Messenger normally, counted from the customer's latest action, such as messaging the Page or tapping a button in the chat. The rule is still in effect in 2026, and messages sent in this window may contain promotional content. After 24 hours, Meta's Messenger Platform policy requires Message Tags, Utility message templates, or paid Marketing Messages instead.

What opens the 24-hour window

Under Meta's Messenger Platform policy, the 24-hour window opens when a user does any of the following with the Page, and the clock runs from the customer's latest action.

Opting in to Marketing Messages does not open a 24-hour window, but if the customer replies to that marketing message, a new 24-hour window opens.

Sends a message to the Page
Taps a call-to-action button in the chat, such as Get Started
Clicks a Click-to-Messenger ad and starts messaging
Starts a chat through a plugin, such as Send to Messenger or Checkbox
Clicks an m.me link with a ref parameter in an existing conversation
Reacts to a message

What you can send inside the 24-hour window

Businesses have 24 hours to reply to a customer, and messages sent in this period may contain promotional content.

On the API side, messages with messaging_type set to RESPONSE or UPDATE may or may not be promotional, but they can only be sent inside the 24-hour window.

What you can do after 24 hours

Once the window closes, regular messages sent through Meta's API fail with error code 10, subcode 2018278, meaning the message was sent outside of the allowed window. Meta's Send API documentation lists these options:

The BroadTurbo web app sends regular broadcasts only to customers still inside the 24-hour window. For customers past 24 hours, it offers sending with Meta's Utility message templates, which must not contain promotional content.

Message Tags, for specific cases Meta defines, with no promotions
Utility message templates, for order, account or appointment updates, with no marketing content
Paid Marketing Messages, for sending promotions to people who opted in

What sellers who broadcast should do

Send promotions to customers who messaged within the last 24 hours first, since that is when promotional content is allowed as normal.
Encourage customers to message you or tap a button in the chat to open a new 24-hour window.
Label customers by conversation cycle so you can separate those still inside the 24-hour window from those past it.
For customers past 24 hours, pick the channel by content: Utility templates for order updates, Marketing Messages for promotions.
If you hit error 10 / 2018278, that customer is outside the window. Don't resend the same way.

Need to message customers who last wrote more than 24 hours ago? See sending with Facebook-approved templates

FAQ: The 24-hour rule

Does the Facebook Page 24-hour rule still apply in 2026?: Yes, it is still in effect. Meta's Messenger Platform policy (updated April 6, 2026) still lets businesses reply to customers within 24 hours, and messages in this period may contain promotional content.
A customer last messaged more than 24 hours ago. Can I send them a promotion?: Not with a regular message. To send a promotion you need Marketing Messages, which are paid and can only go to people who opted in. Message Tags and Utility templates must not contain promotions.
Does a customer reacting to a message open a new 24-hour window?: Yes. Under Meta's Messenger Platform policy, reacting to a message is one of the actions that opens the 24-hour window, just like messaging the Page or tapping Get Started.
What does error 2018278 mean in Messenger?: Error code 10, subcode 2018278 means the message was sent outside the allowed window: that customer is past the 24-hour window. You have to wait for the customer to contact you again, or use another channel Meta allows.

Sources

Last checked against Meta's documentation on September 14, 2026

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What opens the 24-hour window

Under Meta's Messenger Platform policy, the 24-hour window opens when a user does any of the following with the Page, and the clock runs from the customer's latest action.

Opting in to Marketing Messages does not open a 24-hour window, but if the customer replies to that marketing message, a new 24-hour window opens.

Sends a message to the Page

Taps a call-to-action button in the chat, such as Get Started

Clicks a Click-to-Messenger ad and starts messaging

Starts a chat through a plugin, such as Send to Messenger or Checkbox

Clicks an m.me link with a ref parameter in an existing conversation

Reacts to a message

What you can do after 24 hours

Message Tags, for specific cases Meta defines, with no promotions

Utility message templates, for order, account or appointment updates, with no marketing content

Paid Marketing Messages, for sending promotions to people who opted in

What sellers who broadcast should do

Send promotions to customers who messaged within the last 24 hours first, since that is when promotional content is allowed as normal.

Encourage customers to message you or tap a button in the chat to open a new 24-hour window.

Label customers by conversation cycle so you can separate those still inside the 24-hour window from those past it.

For customers past 24 hours, pick the channel by content: Utility templates for order updates, Marketing Messages for promotions.

If you hit error 10 / 2018278, that customer is outside the window. Don't resend the same way.

Need to message customers who last wrote more than 24 hours ago? See sending with Facebook-approved templates

FAQ: The 24-hour rule

Does the Facebook Page 24-hour rule still apply in 2026?

Yes, it is still in effect. Meta's Messenger Platform policy (updated April 6, 2026) still lets businesses reply to customers within 24 hours, and messages in this period may contain promotional content.

A customer last messaged more than 24 hours ago. Can I send them a promotion?

Not with a regular message. To send a promotion you need Marketing Messages, which are paid and can only go to people who opted in. Message Tags and Utility templates must not contain promotions.

Does a customer reacting to a message open a new 24-hour window?

Yes. Under Meta's Messenger Platform policy, reacting to a message is one of the actions that opens the 24-hour window, just like messaging the Page or tapping Get Started.

What does error 2018278 mean in Messenger?

Error code 10, subcode 2018278 means the message was sent outside the allowed window: that customer is past the 24-hour window. You have to wait for the customer to contact you again, or use another channel Meta allows.