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Use this template to format a customer profile segment for upload to Meta Ads as a Custom Audience from a customer list. Name the file using the customer profile naming conventions.
This isn’t legal advice. Confirm data rights, consent, and current policy requirements with your legal or privacy team before uploading customer data to any ad platform.

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File format

  • CSV or TXT file, one row per person, with a header row identifying each column.
  • Meta hashes raw (unhashed) values automatically on upload. You can also pre-hash with MD5 or SHA-256 yourself.
  • A Custom Audience needs at least 100 people before Meta will let you use it for targeting. Check Meta’s current per-file size limit before a very large upload, since oversized files need to be split into batches.

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Column template

Meta matches on any of the columns below. Include only the identifiers you actually have; more matched columns generally means a better match rate.

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Format rules

If you pre-hash a column yourself, normalize it first (lowercase, trimmed), then hash with SHA-256. Mixed capitalization before hashing is a common cause of a match rate that’s lower than it should be.

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Data and compliance rules

  • You need a lawful basis, and for EU/UK data subjects, documented consent, to use each person’s data for advertising. Meta’s Custom Audience Terms require you to certify this before the audience can be created.
  • Don’t upload data tied to sensitive categories: health conditions, financial status, ethnicity, political beliefs, religious affiliation, sexual orientation, or union membership.
  • Don’t upload data obtained from scraping or from a data broker without the rights to use it for advertising.
  • If this audience will run a housing, employment, or credit ad, it falls under Meta’s Special Ad Category rules. You must certify the campaign, and as of March 2025 a Special Ad Category customer list can no longer be shared across business portfolios: upload it directly to each ad account that needs it.

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Official documentation

The finished file is a data file, not a document. Save it to the audience list store, behind access control, and record who supplied it, on what criteria, as of when, and when it expires. Never paste rows from it into a brief, a ticket, or a chat message.
Last modified on August 11, 2026