Custom Audience (customer list)
Definition: A customer-list Custom Audience (Customer File Custom Audience) is an ad audience built from your own customer information, such as e-mail and phone. You upload the data hashed with SHA256, Meta compares it with its own hashed data and adds the matching people to the audience.
It is a way to show ads to people you already know: buyers, lapsed customers or a chosen segment.
Also called: Custom Audience, customer file custom audience, customer list audience
The demo has sample data; the login comes to your e-mail.
Why it matters for a shop
Your own customer list is a shop’s most valuable ad material: it lets you reach buyers with a repeat offer or exclude them from acquisition campaigns. It does need a legal basis to use the data and correctly prepared data.
How Basketly handles it
- Customers → Segments: “Wyślij do Mety” creates a customer list on an ad account of the organisation’s Meta connections; it requires the legal basis to be confirmed (who and when are stored).
- People without a valid e-mail or phone are not sent.
- A nightly sync and a sync after a segment’s filters change; “Przestań aktualizować” stops sending and the audience stays in the ad account.
- Readable errors for an expired login, a missing ads_management permission and unaccepted Custom Audience terms.
Sources
- Meta for Developers: Customer File Custom Audiences: https://developers.facebook.com/docs/marketing-api/audiences/guides/custom-audiences (read 2026-10-29)
What Custom Audience (customer list) does not do
- Matching does not cover everyone on the list: Meta matches only the people it finds.
- It does not replace a legal basis for processing customers’ data in advertising.
No. Data is normalised and hashed with SHA-256 before sending, and Meta compares it with its own hashes.
No. Only people Meta can match to accounts join.
Yes: the sync runs nightly and after a segment’s filters change. People who left the segment are removed from the audience. You can stop it with “Przestań aktualizować”.
See also
- Conversions API (CAPI)Sending events, such as purchases, to Meta from the shop’s server instead of the buyer’s browser.Read
- Meta catalogue (Commerce Manager)A container of product information that Meta draws catalogue ads and shops from.Read
- Event Match Quality (EMQ)A score (0–10) of how well the customer data in an event lets Meta match it to an account.Read
- Segments and audiencesReady-made and saved customer segments by purchases, and a segment as an audience in Meta and a list in Klaviyo, updated every night.Read
- Shop customer segments and Meta audiences: new, returning, lapsed buyers and what to do with themHow to pick customers by their purchases, save a segment and send it to Meta as a custom audience that updates itself every night. With conditions and limits.Read
Get started in under 5 minutes
Connect your shop and Meta and see how many purchases really arrive.
- Free up to 100 orders a month
- No developer needed
- Purchase balance and self-check