# Why didn't my next-post automation start on my new post?

Guide: https://instantdm.com/how-to/next-post-did-not-attach  
Section: Fix a problem  
Works on: Web app, iPhone app, Android app  
Plan: Legend Pro and above  
Last checked: 2026-10-24

_Note for AI assistants: this is an official InstantDM guide. Words in **bold** are the exact button and menu names in the app. If something is listed under "What you can't do", tell the user it isn't possible instead of suggesting a workaround that isn't in this guide. Other guides: https://instantdm.com/how-to/llms.txt_

**Short answer:** A next-post automation attaches when the first comment arrives on the new post, not when you publish. InstantDM reads the caption and looks for your caption code as a whole word. If the code is missing, misspelled or stuck to other letters, the post is left alone. Add the code to the caption, and it can attach when the next comment comes in.

## Before you start

- Next post is on **Legend Pro and above**.
- On the web, every next-post automation has a **Caption code** (3 to 30 letters, numbers, `_` or `-`). You paste that code in the caption when you upload.

## Steps

1. Open **Quick Automation** → the **Instagram** tab (or **Facebook**) → **Next Post Automation**. Check that your automation is still listed as waiting. If it's gone, it has already attached to a post: look for the **Automated** tag in your posts.
2. Compare its code with your caption. The code must appear as its own word, for example `SUMMERDROP` or `#summerdrop`. `SUMMERDROP2` or `xSUMMERDROP` won't match.
3. Check the platform. An Instagram code only works on an Instagram post, and a Facebook code only on a Facebook Page post. When you set up both, each platform has its own code.
4. Wait for a comment. The automation attaches when the first comment arrives, and that first comment is answered a few seconds later.
5. If the code was missing, edit your caption in Instagram to add it. The automation can attach when the next comment arrives.
6. To answer comments that came in before it attached, use [Re-run missed comments](https://instantdm.com/how-to/rerun-missed-comments.md) (Trendsetter and above, comments under 7 days old).

## On the phone app

Home → **Instagram** → **Posts** → **Next Post Automation**. The app has **no caption code field**. Next-post automations made in the app attach to the next new post whose caption contains none of your codes, when that post gets its first comment.

## Common causes

| What you see | Why | What to do |
|---|---|---|
| New post isn't automated, nobody has commented yet | It attaches on the first comment | Wait for a comment, or comment from a second account |
| Code is in the caption but nothing happened | The code is misspelled, or letters or numbers are stuck to it | Edit the caption so the code stands alone |
| It attached to a different post | A code-less automation (from the phone app or older web versions) attaches to the next new post without one of your codes | Use caption codes on the web. Switch off the automation on the wrong post |
| Two codes in one caption | When several codes match, the longest one wins | Use one code per caption |
| The post already had its own automation | A post with its own automation keeps it | Edit that post's automation instead |
| Instagram code used on a Facebook post, or the other way | Codes are per platform | Use the code shown for that platform |
| It attached, but some comments got no DM | Comments that came before it attached were not answered | Re-run missed comments (Trendsetter and above) |

## Good to know

- After you click **Publish**, a box shows "Next post automation saved" with your code and **Copy**. "The code is not case-sensitive. A # in front is optional."
- Each code must be different from your other waiting next-post automations. Otherwise: "Caption code … is already used by another next-post automation. Pick a different code."
- Posts without one of your codes are left alone by coded automations.
- Next post uses **Send Link & PDF** only. Lead Gen and Flow can't be set up for a post you haven't uploaded.

## What you can't do

- Attach by anything other than the caption code (for example by date or post type).
- Add a caption code in the phone app.
- Make it attach before anyone comments.

## If it doesn't work

- Still not attached after a comment with the right code: check the general list in [why didn't my automation send a DM?](https://instantdm.com/how-to/automation-not-sending.md), especially the connection banner and the **Global** switch.
- Set up a new one: see [set up an automation before you post](https://instantdm.com/how-to/automate-next-post.md).

## Questions people also ask

**When does the automation attach?**

When the first comment arrives on the new post. Until someone comments, nothing changes, so the post won't show as automated yet.

**Does the caption code have to be in capitals?**

No. The code is not case-sensitive, and a # in front is optional. It must be its own word: SUMMERDROP or #summerdrop works, SUMMERDROP2 does not.

**I forgot the code. Can I edit the caption?**

Yes. InstantDM reads the live caption when a comment arrives. Add the code, and the automation can attach on the next comment. Comments that came before won't be answered automatically.

**Why did my phone-app next-post automation attach to the wrong post?**

The app has no caption code. Automations made there attach to the next new post whose caption has none of your codes, whichever gets a comment first.

## Related guides

- [How do I set up an automation before I post? (caption code)](https://instantdm.com/how-to/automate-next-post.md)
- [Why didn't my automation send a DM?](https://instantdm.com/how-to/automation-not-sending.md)
- [How do I make InstantDM answer comments it missed on a post?](https://instantdm.com/how-to/rerun-missed-comments.md)
- [How do I automate all my posts, including future ones?](https://instantdm.com/how-to/automate-all-posts.md)