What Is a Custom Audience in Meta Ads?

Most targeting options describe strangers. A custom audience describes people who have already met your brand: they bought from you, browsed your site, opened your app or watched your video. Meta lets you turn those people into an audience you can include in an ad set, exclude from it, or hand to Meta as the seed for a lookalike audience. Each ad account can hold up to 500 custom audiences.

What types of custom audience can I build?

Meta splits them into two families: audiences built from your own business data, and audiences built from engagement with your content on Facebook, Instagram, WhatsApp and Threads.

Type	Built from	Family
Website	Visits tracked by the Meta Pixel	Your data
App activity	Actions people took in your mobile app	Your data
Catalog	Interactions with items in your product catalog	Your data
Customer list	Emails or phone numbers you upload	Your data
Offline activity	In-store purchases or other offline interactions	Your data

The engagement family covers video viewers, lead form openers or submitters, Instant Experience interactions, Facebook or Instagram shop activity, Instagram account interactions, Facebook event responses, Facebook Page interactions and Marketplace listing interactions.

How does a customer list audience match people?

You upload identifiers such as email, phone number and address. Meta hashes this information before use, then matches the hashed values to profiles on its technologies so you can show ads to those customers on Facebook, Instagram and Audience Network. The more identifiers you supply, the better the match rate. Meta says it learns no new identifying information about your customers from hashed data.

To create one, Meta requires you to own the ad account connected to a business portfolio, or hold admin or advertiser permission on it. Meta adds that new accounts may wait a few weeks before they can create or share a customer list audience. A “Match score” column shows, out of ten, how well your last upload matched. A list not updated in over 30 days shows as “Outdated”.

What information must I never upload?

Meta prohibits sharing sensitive information in a customer list. That includes health information, financial information such as card or bank account numbers and credit scores, government identifiers such as social security numbers, passwords, GPS coordinates, and information about children under 13. The audience’s name and criteria must not reflect or imply prohibited information either.

Can a custom audience be used only for exclusions?

Yes. When you add a customer list, you can mark it “only exclusions”, which suits people who opted out of marketing. Anyone in the ad account will see it greyed out under inclusions. Meta notes this choice can’t be changed later and the audience can’t be used to make a lookalike audience.

FAQ

How long do engagement custom audiences keep people?

You pick a lookback period when you create the audience. If you choose 30 days, someone who engaged 29 days ago is included, then drops out the next day unless they engage again. New engagers within the window are added, so the audience refreshes itself without edits.

Does editing a customer list reset my learning phase?

No. Meta says adding, removing or replacing customers in a customer list audience updates every ad set and lookalike audience that uses it, but these changes don’t reset your campaign’s learning phase. Updates can take a few hours, and your ads keep running in the meantime.

Can I use a custom audience to find new customers?

Yes, in two ways. You can use it as the source for a lookalike audience, which reaches people similar to it. You can also include it as a suggestion in Advantage+ audience, which lets Meta deliver beyond the original list when that is likely to improve performance.