• You must be the owner of the ad account connected to a business portfolio, or have admin or advertiser permissions on the ad account which is connected to a business portfolio.
  

 If your account is new or if you’ve recently linked to an existing account, it may take a few weeks before you’re able to create or share a customer list custom audience. If your new account is part of a tenured business portfolio, you may be able to go through business verification.

• Your customer list custom audience cannot be named, include, or be based on prohibited information, which includes information that is or is based on, directly or otherwise, social security numbers, health information, financial information, consumer report information, or other categories of sensitive information (including any information defined as sensitive under applicable laws, regulations, or industry guidelines), or information that is otherwise not allowed under our terms. Learn more about prohibited information.
  

1. Open Audiences in Ads Manager.
2. Select Create audience then Custom audience.
   If you haven't created an audience before, select Create a custom audience.
3. Select Customer list, then Next.
   • Prepare list: Follow the instructions to format your customer list. Select Next.
   • Add list: You can Upload a file or Paste comma-separated values. Let us know if your file includes a customer value column. You can choose an Audience label, Audience name and Description to help you identify and find your custom audience. Accept the custom audience terms, then select Next.
   • Match columns:

     •  The check icon means your identifiers were mapped correctly and are ready to be hashed, then used for the matching process.
     •  The exclamation point means either that you chose not to include certain identifiers or that some identifiers need to be manually updated. You have higher chances of getting a better match rate to build your audience if you make the corrections before uploading your file.
4. Select Import and create.

You'll return to Audience and see your audience Populating.

We’ll let you know when your audience is Ready. Then you can create an ad to reach your new custom audience, or create a lookalike audience to find new people who share similar behaviors and interests with your existing customers.

Your customer list is hashed and will be unidentifiable at an individual level. Hashing is a type of cryptographic security method that turns your identifiers into randomized code and cannot be reversed. (Depending on the size of your list, this may take a few minutes.)