Using an existing post in a Facebook ad: what is kept?
To use an existing Facebook Page post in an ad, choose Use existing post in Ad setup, then Select post in Ad creative. Meta separately documents carrying existing ad engagement through a checkbox when duplicating an ad. The pages used here do not establish a general promise that Use existing post, a later edit or Create a new post keeps or loses reactions and comments.
On this page9 sections
How do you create an ad from an existing post?
Use the instructions for the platform of the source post. The Facebook Page post page and Instagram post page, checked 20 Oct 2026, describe separate routes; a matching picture on both platforms is not a reason to merge their instructions.
Existing Facebook Page post
- In Meta Ads Manager, click + Create, choose the objective and configure the campaign and ad set.
- Under Identity, select the Page and Instagram account, if applicable.
- Under Ad setup, choose Use existing post.
- Under Ad creative, click Select post.
- Choose the post in the Select post window and click Continue.
Compatibility still matters. Meta says some posts may not work with the chosen objective. A post whose existing call to action has a different goal cannot be used to create that ad: its example is a Shop now post that cannot become a call ad.
Existing Instagram post
In the Instagram instructions, select the Instagram account under Identity, then Use existing post to find recent Feed, Reels and Stories content. For an older post, that page describes finding it with the unique code at the end of its Instagram.com URL.
The Facebook creation page also says an existing Instagram story must be active to be selected: archived stories and stories added to highlights cannot be selected in that described route. This condition is about selecting an existing story, not a rule for all Instagram creative.
Our suggestion: record the source platform, account, post and intended objective before choosing a route. Do not solve a compatibility problem by assuming that a different Post ID or a matching image makes the post eligible.
Where do you find the right Post ID?
For a Facebook Page post, Meta’s creation instructions say to avoid post IDs copied from a URL. They point to the ID column in Page posts when searching for the post to advertise.
The dedicated Page post ID instructions describe another route: open Meta Business Suite → Content → Published, select the post and read its Page post ID in Post details. That page defines the ID as identifying an individual post from the Page.
Both descriptions are retained here: one points to a column in Page posts and the other to Post details in Business Suite. These pages do not explain why the routes differ. Our suggestion is to use the documented route available to you and record where the ID came from.
| Documented source of the ID | Boundary to preserve | |
|---|---|---|
| Facebook Page post | The creation page says to use the ID column in Page posts; the dedicated ID page gives Business Suite → Content → Published → Post details. | Do not substitute a number copied from the Facebook post URL for those instructions. |
| Older Instagram post | The Instagram page explicitly allows the unique code at the end of the post’s Instagram.com URL to find it in Use existing post. | The Facebook URL warning does not cancel this Instagram-specific instruction; the Instagram instruction does not authorise Facebook URL extraction. |
Ad ID and Post ID identify different objects
Meta’s ad-ID page describes unique IDs for campaigns, ad sets and ads. Its route is Columns → Customise columns → Settings → Object names and IDs, where you can select Campaign ID, Ad set ID or Ad ID. An Ad ID is not the Page post ID described above.
Our suggestion: label each identifier in a handover, rather than calling every number “the ID”. The ad-ID page used here does not describe creative IDs; this article does not turn it into instructions for obtaining a post identity from a creative.
What does Meta document about engagement?
Meta explicitly describes carrying existing ad engagement in its Duplicate instructions. Select the ads, click Duplicate, choose Original, Existing or New campaign and the number of copies, then use the engagement checkbox before completing Duplicate.
Show existing reactions, comments and shares on new ads.
For creative customised for specific placements, the same page says existing engagement cannot be carried over more than once when duplicating. This is a qualified restriction on repeated carrying of engagement, not a statement that the option never exists for customised creative.
That is a Duplicate workflow. The creation instructions in the first section use Use existing post. Our reading: evidence for the checkbox does not, by itself, prove that both workflows have identical behaviour or that future comments will be shared between all resulting ads.
The Facebook-to-Instagram limitation has a direction
The Instagram page describes a Facebook and Instagram post with the same content. If you create the ad from the existing Facebook post for an Instagram placement, total engagement metrics, such as likes, will not show engagement from that Instagram post.
Keep the source and destination in that order. The statement does not establish every Instagram-to-Facebook case or every way of duplicating an ad. For placement selection as a separate decision, see placements and lead quality.
Different tools count different result scopes
The results-troubleshooting page distinguishes paid and organic results and the platforms each tool includes. These are three rows from that distinction, not a formula promising that every displayed total will reconcile.
| Result scope described by Meta | Our suggested comparison check | |
|---|---|---|
| Ads Manager | Paid results from Facebook, Instagram and Meta Audience Network; no organic results. | Compare the same metric and period, retaining the paid and platform scope. |
| Facebook posts data | Paid Facebook and organic Facebook results; it does not include paid Instagram results. | A Facebook post total is not the same scope as paid results across Meta placements. |
| Instagram Insights | Paid and organic Instagram results. | Do not treat that total as organic-only or as an aggregate of all Facebook and Instagram activity. |
Our suggestion: note the tool, metric, period, platform and paid/organic scope beside each observation. If the numbers differ, first establish whether the scopes match; a mismatch alone does not prove reactions were transferred, removed or combined.
What Meta’s pages do not say
The seven Meta pages used here do not describe a general rule for keeping or losing reactions, comments and shares when you choose Use existing post, later switch to Create a new post or edit an ad created from a post.
The Duplicate page documents carrying existing engagement with its checkbox. These pages do not establish a universal shared stream of future comments, all Facebook/Instagram differences in duplication or what happens in every combination of post, form and placement.
They also do not explain why an individual editor might display an ad as an existing post when its owner expected another creation route. A description of that screen is an observation to investigate, not proof of the route or the eventual engagement behaviour.
Keep the unanswered question visible
Our reading: missing documentation is not a promise of loss, a promise of preservation or proof that a feature does not exist. Do not turn a plausible workflow into a guarantee about every reaction or future comment.
Our suggestion: ask the person managing the ad to identify the exact source platform, route and placement, and the specific behaviour they can substantiate. If the decision depends on preserving every comment, resolve that point before treating it as an agreed outcome.
What can stop an existing-post ad from being edited?
Meta’s editing-troubleshooting page gives specific limits. If a Page post has been deleted, it cannot be used to create new ads or edit ads that include it; Meta directs you to create a new ad or choose a different post.
The same page says call-to-action buttons cannot be edited for ads that use an existing post. It also says an ad created from Meta Business Suite or a Facebook Page cannot be edited, deleted or duplicated in Ads Manager. The place where the ad was created therefore matters.
Separately, the creation page says modifying details such as adding a phone number also changes the selected original post. During that creation route, removing an existing call to action removes it from both the ad and post. The Remove button may be unavailable when a call to action is required to publish.
These statements concern different operations: details during creation versus limits on editing an existing ad. Do not read the creation example as a universal right to edit every existing-post CTA, or the editing restriction as proof that no creation-time detail can affect the post.
Our reading: none of those editing limits establishes that changing media or text always erases engagement. For a performance decision before another edit, use the separate budget-increase guide; the ID alone is not evidence of a business result.
What can Variafy tell you about an existing post?
Variafy is in the free beta, with Meta and Google Ads support live; Google access is read-only. Its Meta creative read can return a creative identifier, a yes/no indication that the creative comes from a Page post and the associated ads.
It does not return the actual Post ID. That yes/no field is not a post identifier, and a creative identifier does not become one by renaming it. A person needs to obtain and label the post identity using Meta’s appropriate interface.
The product does not read ad-comment text, merge engagement or promise to transfer it. It cannot establish from that flag that future comments are shared, that Facebook and Instagram totals should match or that reusing a post improves cost per acquisition.
Our suggestion for an assistant: “List the returned creative identifiers, Page-post indications and associated ads. Mark the actual Post ID as unavailable. Keep my manually checked post and metric observations separate; do not infer a shared comment stream or a performance effect.”
What should the handover to the ad manager contain?
Our suggestion: hand over the route and evidence you actually have, with a named person responsible for the unresolved part. The following Willow Studio example is entirely invented; it is a way to organise a decision, not a Meta requirement or a real account observation.
| Filled observation or instruction | Boundary and next action | |
|---|---|---|
| Source and identity | Willow’s autumn post is a Facebook Page post. Ella records its Page post ID from Business Suite → Content → Published → Post details in the team’s private task. | The public example contains no real ID. The ad identifier is labelled separately; no product-generated Post ID is assumed. |
| Creation route | Ella asks Noor to use the existing Facebook post and record the chosen placements. This is not an instruction to use Duplicate. | If Noor instead proposes Duplicate, she must identify that route and its engagement option explicitly. The two processes are not silently interchangeable. |
| Engagement observation | Ella has a Facebook posts-data observation; Noor has an Ads Manager observation. They have not yet recorded the same metric and period. | Mark the comparison unresolved. First match metric, dates, platform and paid/organic scope; do not declare lost likes from the difference. |
| Decision and owner | At the invented 20 Oct checkpoint, Noor owns the source/route check and Ella owns the metric comparison. Future comment sharing is not an agreed result. | If future sharing is essential to the brief, request evidence for that exact case before relying on it. No CPA or engagement uplift is promised. |
Copyable existing-post brief
Source platform/account/post: __. Post ID and where it was obtained: __. Separate Ad ID: __. Use existing post or Duplicate: __. Objective/CTA and placements: __. Tool/metric/period/platform/paid-organic scope: __. Observed result: __. Behaviour still unproven: __. Next check, owner and date: __.
For the separate task of handling comments, use the ad-comments guide; for a wider account investigation, use the Meta audit. This handover concerns source identity, documented operations and the exact engagement question still open.
How we checked
Based on 7 different Meta Help documents: Facebook existing-post creation, Instagram existing-post creation, Page post ID, ad IDs, duplicating ads, editing troubleshooting and differences between results tools; checked 20 Oct 2026.
The Facebook and Instagram URL instructions, two Page-post-ID routes, Duplicate option and editing/creation scopes are kept distinct. The unanswered engagement questions are limited to these pages, not claims about every Meta feature.
The Willow example and handover are invented. Product scope was checked against the implementation: the creative read returns an indication of a Page post, not its actual Post ID.
Questions
How do I use an existing Facebook Page post in an ad?
In Ads Manager, create and configure the campaign and ad set, select the Page under Identity, choose Use existing post in Ad setup, then Select post in Ad creative. Select the post and Continue. Compatibility with the objective and existing CTA still matters.
Can I copy the Post ID from the URL?
Meta advises against using IDs copied from Facebook post URLs and points to the ID column in Page posts. Its dedicated Page-ID page also gives a Business Suite route. For an older Instagram post, the Instagram instructions explicitly allow the unique code at the end of its Instagram.com URL.
Does using an existing post guarantee that likes and comments are kept?
The pages used here do not establish a general keep-or-lose rule for Use existing post, Create a new post or later edits. The Duplicate page separately documents carrying existing engagement through its checkbox; that is not a universal promise about future shared comments.
Will the Instagram post’s likes appear when I advertise the Facebook post on Instagram?
For the case of Facebook and Instagram posts with the same content, Meta says an ad made from the existing Facebook post for an Instagram placement will not show the Instagram post’s engagement in its total engagement metrics. That statement should not be reversed into a claim about every Instagram-to-Facebook case.
Can I edit the call-to-action button on an existing-post ad?
Meta’s editing-troubleshooting page says CTA buttons cannot be edited for ads using an existing post. Its creation instructions separately describe changes such as phone details and removing a CTA, with conditions. Keep those creation-time examples separate from the editing restriction.
Can Variafy find the actual Post ID or combine comments?
No. Its creative read returns a creative identifier, a yes/no indication that it comes from a Page post and associated ads. The actual Post ID and ad-comment text are not returned, and it does not merge engagement. Obtain the post identity manually in the appropriate Meta interface.