Short answer: the first automated message is limited to one per comment. After the person replies or taps a button, more messages are allowed for 24 hours.
The rules behind it
- One private reply per comment. When someone comments, Instagram lets your account send them one message in reply to that comment, within seven days.
- The 24-hour window. Once the person messages you back, or taps a button in your message, a conversation is open and you can send more messages for 24 hours.
That is why good comment-to-DM tools send an opening message with a button first. The tap opens the conversation, and the link arrives as the second message.
What the two-step flow looks like
- Comment: "price"
- Opening DM: "Hi! Tap below and I'll send the price list." [Button: Send it]
- They tap.
- Second DM: the price list link (and, if you use one, a follow check first).
You can also skip step 2 and send the link straight away in the first message. That is simpler, but the conversation stays closed unless they reply.
After the window
After 24 hours with no reply from the person, automated messages stop. You can still reply personally, within Instagram's rules for human replies. See the human agent tag.
Related reading
Frequently asked questions
Why does my tool send a button first instead of the link?
Because the tap opens a conversation, so the link and any follow-up can be sent within Instagram's rules.
Can I send a follow-up message the next day?
Not automatically, unless the person replied within the last 24 hours.
Does the button step lose people?
A few, but it opens the chat properly and makes follow-gates possible. You can turn it off and send the link directly.