Follow these steps to apply placement exclusion lists to your PMax campaigns. This guide shows you how to:
Create a placement exclusion list in Google Ads (Google's instructions).
Add it at the MCC level and then manually apply it to the individual accounts you manage under it (child accounts).
Once done, it will block placements for all campaigns (whether populated manually or through Auto-Apply), including Performance Max campaigns.
Note: this method doesn't need Google Ads support to apply the list to Performance Max.
Requirements before you get started:
You need an MCC structure
Make sure you have edit rights to create placement exclusion lists on MCC level
Note
Each MCC account can create up to 3 placement exclusion lists with a maximum of 250,000 exclusions per list
You can't exclude placements at the campaign level for Performance Max campaigns; they are managed at the account level
1. Create a placement exclusion list in Google Ads
Create placement exclusion lists at the MCC level to apply them to Performance Max campaigns. Refer to Google's guide for instructions.
2. Add it at the MCC (Manager Account) level and manually apply it to child accounts
Sign in to your Manager Account
Go to Sub-account settings under the Accounts icon
Select the accounts where you want to apply the list. (Note: Sub-manager accounts cannot use exclusion lists)
Click Edit > Add Placement Exclusion Lists
Select the list(s) and click Apply
Please refer to the Google's article for more details.
Troubleshooting
Please note that synchronization typically takes up to 72 hours after your list is implemented in your Ads account. During this time, you might still see the excluded sites appearing in your reports.