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Custom audience

  • Updated October 22, 2026

A custom audience is a Meta audience made of people who already know your business: visitors tracked by your Meta Pixel, people who use your app, a customer list you upload, or people who engaged with your content on Facebook, Instagram, WhatsApp or Threads. You can target it, exclude it from an ad set, or use it as the source for a lookalike audience.

How does Meta define a custom audience?

From Meta's About custom audiences:

A custom audience lets advertisers build audiences from their own data sources or Meta engagement data for retargeting campaigns, new customer campaigns and other ad targeting options.

The same page sets the limit: "You can create up to 500 custom audiences per ad account." Retargeting means including the audience. A new customer campaign means excluding it: Meta's page on using them gives the example that "you can exclude an audience of your current customers if you're running a campaign to gain new customers."

What types of custom audience are there?

Meta sorts them into two groups. The first is built from your own data:

TypeWhat Meta says it targets
Website"people who visited your website, tracked via the Meta Pixel"
App activity"people who took specific actions in your mobile app"
Catalog"people who interacted with items in your product catalog"
Customer list"Upload a list of customer emails or phone numbers to match with Meta users"
Offline activity"people based on in-store purchases or other offline interactions"

The second is built from engagement on Meta's apps: video, lead form, Instant Experience, shopping, Instagram account, events, Facebook Page and On-Facebook listings. Two details change what ends up inside. An engagement audience keeps a rolling window: if you choose 30 days and someone engaged 29 days ago, "If that person does not engage again in the next day, they are removed from the audience." A website audience "starts populating from the time you create it (ie, it won't backfill)." A customer list is hashed before matching, and Meta says it "doesn't learn any new identifying information about your customers from hashed data."

Can a custom audience be used only to exclude people?

Any custom audience can be excluded. Meta also offers an exclusion-only custom audience, a customer list that "cannot be used to include people in your audience". It is one-way: "Once you create an exclusion-only custom audience, you cannot change it to a regular custom audience." It can't seed a lookalike, and it isn't available on campaigns under special ad categories.

Will Meta deliver outside my custom audience?

If you include it under Advantage+ audience, it can. Meta's controls and suggestions page lists "Custom audiences to include" as a suggestion and "Custom audiences to exclude" as a control. Meta's Advantage+ custom audience page says the setting lets a custom audience "guide delivery instead of strictly limiting it", and "can enable our systems to deliver ads beyond the original selected audience". To keep it as a hard limit, Meta says you "may have to uncheck the box Use as a suggestion."

Why can't I use my custom audience?

  • It hasn't populated. Meta: "It should show Ready, under Status". A customer list shows Outdated when it "hasn't been updated in over 30 days".
  • It was flagged. Meta's restrictions page says audiences that reference "specific health conditions (e.g., arthritis) or financial status (e.g., credit score)" are flagged and "cannot be used for running ad campaigns".
  • It's built from a deleted Page. Ad sets get "30 days after the Page's deletion date" to update or remove it. After that, they are paused and the audience is deleted.
  • The ad reaches young people. For audiences that include people under 18 (or older in some countries), you "can't use detailed targeting, custom audiences, Lookalike Audiences or saved audiences".

What it means for your ads

  • Give retargeting its own creative. Meta describes a customer list as people "who have already shown an interest in your business or product". An ad made for strangers gives them nothing new.
  • Exclude buyers from prospecting. It's the example Meta gives.
  • Build your best source first. A custom audience can be the source of a lookalike audience, so its quality carries over.

Common mistakes

  • Treating an included audience as a fence. With Advantage+ audience on, it's a suggestion unless you make it a control.
  • Expecting history on day one. A new website audience starts empty.

Sources

Meta revises these pages without notice, so check the source before acting on any of it.

Terrads makes a batch of different ads in one go, so a retargeting audience that has seen your first ad gets a new angle instead of the same one again.