What this does

A Meta Custom Audience sync keeps a Meta Custom Audience in step with an OnVoard segment. OnVoard creates the audience, owns it, and refreshes its membership for you. You can then target that audience in your ad campaigns, exclude it (for example, suppress existing customers from a prospecting campaign), or use it as the source for a Lookalike Audience.

Contacts are matched to Meta users on hashed email and phone number. Nothing is matched using cookies, so the sync keeps working regardless of browser tracking restrictions.

Before you start

Meta enforces a few requirements before any customer list audience can be created. OnVoard cannot satisfy these for you, and each one shows up as an error from Meta when you try to create a sync. Please set all of them up first.

1. Your ad account must be owned by a business portfolio

Meta does not allow customer list audiences in a personal ad account. The ad account has to be owned by a business portfolio (this used to be called Business Manager).

If you see this error:

To create or edit a Custom Audience made from a customer list, your admin needs to add this ad account to a business.

then the ad account you picked is a personal one. To fix it:

  1. Go to business.facebook.com and create a business portfolio if you do not have one already.

  2. Open Business settings, then Accounts, then Ad accounts.

  3. Either create a new ad account inside the business portfolio, or add your existing one.

Please note the difference before you choose. Creating a new ad account inside the business portfolio is clean and reversible. Adding an existing personal ad account permanently transfers ownership of it to the business portfolio, and Meta does not let you undo that.

2. You must accept Meta's custom audience terms

The terms have to be accepted once for each ad account. Meta only tells you about this by rejecting the audience, with an error like:

Custom audience terms not accepted. To create or edit an audience with an uploaded customer list, agree to the custom audience terms at https://business.facebook.com/ads/manage/customaudiences/tos/?act=YOUR_AD_ACCOUNT_ID

Open that link and accept the terms. The link is specific to one ad account, so if you use more than one ad account you need to accept the terms for each of them. OnVoard also shows this link in the Create Audience Sync window once you pick an ad account.

3. You need admin access

The Facebook account you connect to OnVoard needs admin access to both the business portfolio and the ad account. If your access is limited to something less than admin, Meta will not let OnVoard create or update audiences in that ad account.

Connecting Facebook

  1. In OnVoard, go to Connections, then Meta Custom Audience.

  2. Select Connect Facebook and complete the Facebook login.

  3. Grant access to the ad accounts you want to use when Facebook asks.

Your Facebook login is what OnVoard uses to push audiences. You can review or remove the connection at any time under Connections, then Manage Connections.

Creating an audience sync

  1. Go to Connections, then Meta Custom Audience.

  2. Select Create Audience Sync.

  3. Pick the Segment whose contacts should become the audience members.

  4. Pick the Ad Account that will own the audience.

  5. Optionally set an Audience Name. If you leave it blank, OnVoard names it OnVoard - <segment name>.

  6. Select Create.

The first sync starts straight away. After that, OnVoard refreshes the membership automatically every few hours. You can select Sync Now on any row if you need to push immediately.

Common issues

I do not see my ad account in the list

OnVoard reads the list of ad accounts when you connect Facebook, and stores it with the connection. If you created or were given access to an ad account after connecting, OnVoard has not seen it yet.

Go to Connections, then Manage Connections, and select Resync on the Facebook connection. Then reload the Meta Custom Audience page and the ad account should appear.

If it still does not appear, check that your Facebook account has admin access to that ad account.

The page says "No ad accounts found"

Your Facebook connection worked, but the account you connected has no ad account that OnVoard can manage. This usually means either that you have not created an ad account yet, or that you did not grant access to it during the Facebook login. Select Reconnect Facebook and make sure you allow access to your ad account.

My segment is not in the segment list

Only segments that have finished building can be synced. A segment that is still being calculated has no membership yet, so it is not offered. Wait for the segment to finish, then reload the page.

The audience is empty or smaller than my segment in Meta

This is normal and expected. Two things cause it.

First, Meta only counts people it can match. OnVoard sends hashed email addresses and phone numbers, and Meta can only add someone to the audience if that email or phone matches a Meta account. A match rate below 100 percent is completely normal, and it varies a lot by audience.

Second, Meta needs time to process an upload. It can take up to 24 hours before the audience size in Ads Manager settles. The Last Synced column in OnVoard shows when we last pushed and how many people we sent, which is not the same number as the audience size Meta reports.

Very small audiences may not be usable for ad targeting at all. Meta requires an audience to reach a minimum size before it will deliver ads to it.

A row says "Reconnect needed"

Facebook user access tokens expire roughly every 60 days, and they also stop working if you change your Facebook password or remove OnVoard's access. When that happens, OnVoard cannot push to Meta any more and marks the sync as needing a reconnect.

Select Reconnect Facebook on the Meta Custom Audience page and log in again. Syncing resumes after that.

A row says "Retrying"

A recent push to Meta failed, but the failure looks temporary. OnVoard retries automatically on the next scheduled refresh, so there is nothing for you to do. If the problem keeps happening, the row changes to Error.

A row says "Error"

Pushes to Meta have failed repeatedly and OnVoard has stopped trying. This is almost always one of the setup requirements above, most often the custom audience terms not being accepted for that ad account. Fix the underlying problem, then select Resume Sync on the row.

A row says "Paused"

You paused it. OnVoard is not refreshing the membership, and the audience in Meta stays exactly as it was at the last sync. Select Resume Sync to start refreshing it again.

How the refresh works

Every few hours, OnVoard sends Meta the full current membership of the segment and replaces the audience contents with it. People who left the segment are removed, and people who joined are added.

We deliberately replace the whole membership rather than sending changes one at a time. Replacing is what keeps the audience honest when a contact leaves a segment quietly, and it does not reset the learning phase of any ad set using the audience.

Because the refresh is on a schedule, a contact who joins or leaves a segment is not reflected in Meta instantly. If you need an immediate push, select Sync Now.

Removing a sync

Select Remove Sync on the row. This deletes the sync in OnVoard only. The audience itself is left in place in Meta on purpose, so that any live ad set still targeting it keeps working. The audience simply stops being refreshed and stays at its last synced membership.

If you also want the audience gone, delete it in Meta Ads Manager after removing the sync.