400 Error when i attempt to send qualified audience to FB Custom Audience

Hi ​@Priya, 
 

what you should check before anything else.

1. Add Adobe as a partner in Facebook Business Manager

Think of this like giving Adobe a key to your Facebook account. Without it, no matter how perfectly everything else is set up, Facebook will simply refuse to let AEP push any data in. Go to Facebook Business Manager → Settings → Partners → add Business ID 206617933627973. If this is missing, that's your problem right there.

2. Accept Facebook Custom Audiences Terms of Service

Facebook requires the ad account owner to personally sign an agreement before any custom audience can receive data. It's a one-time step that's easy to miss. The account owner needs to go into Facebook Ads Manager, try to create a Custom Audience manually, and Facebook will show a prompt to accept the terms. Once accepted it unlocks for all tools including AEP.

Nine times out of ten it's one of those two.

Hi ​@Priya  

The issue is not with AEP configuration but due to Facebook API rejecting the request because of permission or account setup issues. 

Similar thread - answered please check here 

So Here are the detailed steps again 

Step 1: Validate Facebook setup

• Business Manager account (NOT personal)
• Ad account linked
• Account active (no restrictions)

Step 2: Accept everything (very important)

• Custom Audience Terms
• Business Tools Terms

Step 3: Check permissions

• You are Admin or Advertiser
• Can manually create audience in FB UI

Step 4: Reconnect in AEP

• Remove destination
• Recreate connection
• Re-authenticate

Step 5: Test small audience

• Send 5–10 profiles only

Hope this helps. 

Thank you.