What Is Instagram's 24-Hour Messaging Rule, and What Can an Automated DM Send?

When someone comments on your post, Instagram lets a business send them one private reply, within 7 days. Anything after that needs the person to respond, and their response opens a 24-hour window for follow-up messages.

That's the short version, and it explains almost every "why does my DM tool work like this?" question you'll run into. If you're a business owner or social media manager setting up comment-to-DM, knowing these rules helps you write automations that actually deliver, and helps you understand why a tool behaves the way it does. Below, we walk through each rule in plain English, quoting Meta's own developer documentation, and show how the rules shape Planoly Automations.

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What Is the 24-Hour Window?

Meta's messaging policy describes a "standard messaging window." In Meta's words, "For most user actions… the standard messaging window lasts 24 hours." When someone messages your business, you have 24 hours to reply through an automated tool.

Comments work a little differently. Meta's private replies documentation says a business can send one private reply per comment, within 7 days of the comment. (For Instagram Live comments, only during the broadcast.) Then: "Follow-up messages can only be sent if the recipient responds, and must be sent within 24 hours of the response."

Put together:

1. Someone comments. You can send one private reply, within 7 days.

2. They respond. That opens the 24-hour window.

3. You follow up. Inside that window, you can send more messages.

Why it matters: A comment alone doesn't open a conversation. The person has to answer before your tool can send the rest.

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Why Does My DM Need a Button?

Because the button is how the person "responds." It turns a one-message limit into a full conversation the person chose to start.

This is exactly why Planoly's opening message exists. Planoly uses Meta's official Instagram API, so its automations follow these rules. Planoly's help article explains it directly: "Instagram allows one private reply to a comment until the person answers, and the tap is that answer. Someone who never taps gets only the opening message."

So in Planoly, the opening message is "a short text with one button." When the person taps it, Planoly sends every message you've added below. If you turn the opening message off on a post, only the first message below it sends, because there was no answer to open the window.

Stories and DMs are different. When someone replies to your story or messages you first, they've already started the conversation, so in Planoly every message in the automation sends either way.

Why it works: Designing around the one-private-reply rule means your second, third and fourth messages actually arrive.

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Can Automated DMs Be Promotional?

Yes, within the window. Meta's policy says: "Messages sent within the standard messaging window may contain promotional content." So once the person has tapped, you can send a product link, a discount or a booking page.

Outside the window, your options shrink. Meta lists a Human Agent tag that allows manual replies by a person "within a separate 7-day period." Meta also says one-time notifications and sponsored messages are "not available for IG Messaging API."

And one bigger rule: Meta's Developer Policies say not to contact people in Instagram Messaging unless you've obtained opt-in. Comment, story-reply and DM automations work because the person reached out first.

Why it matters: This is why "auto DM new followers" and cold outreach aren't what comment-to-DM tools do. The person has to start it.

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What Are the Rate Limits?

Meta's Graph API rate limits page lists "750 calls per hour per Instagram professional account for private replies to comments on Instagram posts and reels."

Meta's rate-limiting page is the official source for this number, so it's the one to go by if you see other figures elsewhere.

For most business owners, 750 an hour is plenty. It becomes relevant when a post goes viral and hundreds of people comment the keyword at once.

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Do I Need to Disclose a Bot?

Meta's Instagram Messaging overview says apps must have an escalation path to a human agent, and it points to disclosure requirements in some places, naming California and Germany as examples. Meta also recommends telling people when they're talking to automation, "even where not legally required."

We're not lawyers, and this isn't legal advice. The practical move is easy anyway: write your opening message so it's obvious it's an automatic reply ("Here's the guide you asked for! I'll follow up personally if you have questions.") and make sure a real person checks the inbox.

Why it works: People are more forgiving of automation when it's upfront, and a real person on the other end keeps the conversation human. Automated threads land in Planoly's Inbox, where you can reply yourself within 24 hours of the person's last message.

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Frequently Asked Questions

What is Instagram's 24-hour rule for DMs?

When someone messages your business, Meta's standard messaging window gives you 24 hours to reply through an automated tool. For comments, you can send one private reply within 7 days, and follow-ups need the person to respond first.

How many private replies can I send to one comment?

One. Meta's documentation allows one private reply per comment, and follow-up messages can only be sent if the person responds.

Can I send promotional messages in Instagram DMs?

Inside the standard messaging window, yes. Meta's policy says messages sent within the window may contain promotional content.

What is the Instagram private reply rate limit?

Meta lists 750 calls per hour per Instagram professional account for private replies to comments on posts and reels.

Why does my automated DM only send the first message?

Usually because the person didn't respond. Without a reply (like tapping a button), Instagram only allows the first private reply to a comment.

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TL;DR

• A comment allows one private reply within 7 days.

• The person's response opens a 24-hour window, and promotional messages are allowed inside it.

• That's why tools like Planoly use an opening message with a button: the tap is the response.

Has the "only my first message sent" problem caught you before? Now you know why. See how Planoly builds around it in the Automations help article.