How long do customer lists typically take to populate via the API?

Hello Molly,

Thank you for using our Microsoft Advertising Learn Q&A Platform! 

I understand that you want to learn more about customer lists on API. I hope the response and resources provided here can be of use to you.

Typically, after uploading a customer list via the API, you should check the Audience Size fields, such as Audience Search Size, after 48 hours to see how many customers have been matched on the Bing Network. If your audiences have not populated after a week, it may be worth reviewing the upload process to ensure that it was completed correctly and that there were no issues during the upload.

The audience queue process on Microsoft’s side generally involves a matching period where the uploaded customer data is processed and matched against existing users on the Bing Network. If there are delays beyond the expected timeframe, it might be beneficial to contact Microsoft Advertising Support for further assistance.

For further information, please see the following help pages:

Customer List Record - Bulk

Audience APIs

Our support teams are also happy to discuss your account in more detail via phone, chat or email to provide review assistance, please see our support page to reach out! 

I hope the information provided here will at least partly answer your question.  If you have any additional questions please do not hesitate to reach out to our support. I have also sent you a private message asking for further details. You are more than welcome to respond to me to that I can begin the investigation on my end.

Kind regards, 

Vahid | Microsoft Advertising Support Specialist | 800-518-5689