Meta's messaging rules for Instagram rest on one idea: a business may message a person only when that person recently messaged the business. The "recently" is 24 hours. Understanding this window explains most of what automation tools can and cannot do.
The rule in one sentence
When someone sends your account a message, you have 24 hours from their last message to reply, including with automated messages. Each new message from them restarts the 24 hours.
What opens the window
- They send you a DM
- They reply to your story
- They tap a button in a message you sent (this counts as a message)
- They click a click-to-DM ad (Meta allows a longer window for these)
What does not open it
- Liking your post
- Following you
- Viewing your story
- Commenting on your post, on its own
Comments are handled differently, through private replies: you may send one message to a commenter, within 7 days of the comment. That single message does not open the 24-hour window by itself. If they reply to it, or tap a button in it, the window opens. See private replies explained.
Why two-step flows exist
This is why many comment-to-DM tools send a short opener with a button first:
- Comment → one private reply: "Tap below and I'll send it" [Send me the link]
- They tap → the 24-hour window opens
- Within the window, the tool can check whether they follow you, send the link and, if useful, a follow-up message
Without the tap, the private reply is the only message you can send.
What happens after 24 hours
Automated messages stop. If the person writes again, a new window opens. For cases where a person on your team needs more time to answer a support question, Meta has a human agent tag that extends the window to 7 days for manual replies. Bots cannot use it. See the human agent tag.
Designing flows that fit
- Put the value in the first reply or make the button irresistible. You may not get a second chance.
- Do not plan sequences like "day 1, day 3, day 7" messages. They break the window.
- Invite a reply. A question like "Want the size chart too?" gets replies, which reopen the window.
- Move ongoing conversations to a channel built for it, such as WhatsApp, with the person's permission.
Frequently asked questions
Does the window apply to messages I send by hand?
The 24-hour rule is about messages sent through the API. Manual messaging in the app follows Instagram's general rules on spam and requests.
Can I send a promotional message to everyone who messaged me last month?
Not through automation. Outside the window, there is no allowed way to send automated marketing DMs on Instagram.
Does a story reaction emoji open the window?
Yes, a reaction is delivered as a message.
Is the window the same on Facebook Messenger?
Messenger has a similar 24-hour standard window. Details differ, so check Meta's documentation for each platform.