How Do Publisher Block Lists Work on Meta Ads?

Think of a block list as a do-not-run list for your ads. You name the places you do not want to appear, then apply the list to your ad accounts. You build and manage it in the Brand Safety and Suitability Center.

What are the two kinds of block list?

Meta describes two types, and they do different jobs.

Type	What it does	Where it applies
Publisher block list	Helps prevent ads running on specific Pages, profiles and apps	Apps in Meta Audience Network, Facebook in-stream reels, Facebook profile feed, ads on Facebook Reels and Instagram profile feed
Content block list	Helps prevent ads appearing near content you find unsuitable	Feed ads and reels feed ads on Facebook and Instagram, and Threads feed ads

Content block lists are available through brand safety and suitability Meta business partners. Meta says that at the time of checking you can only see content block lists applied from the Brand Safety and Suitability Center, so ask the partner to review the content that was actually blocked.

How do you build a publisher block list?

Meta gives you three routes. Pick the one that matches what you already know.

Route	How it works
Partner-publisher lists	Choose a placement type, tick the publishers, click Add to publisher block list, then save
Delivery reports	Start from a report of where your ads appeared, in one of four types: Facebook in-stream reels, ads on Facebook Reels, Audience Network rewarded videos, or Audience Network native, banner and interstitial
A file you create	Make a .csv or .txt file with URLs in column A, then upload it

For the file route, Meta says to include the Facebook Page URLs, Instagram account URLs and app store URLs of the publishers you want to block on certain placements. To block a Facebook Page for the Facebook in-stream reels placement, Meta’s format is https://www.facebook.com/ followed by the Page ID. A list cannot contain more than 10,000 lines because of technical constraints, so use several files if you need more.

How do you upload and apply a list?

1. Click Publisher block lists in the left menu of the Brand Safety and Suitability Center.
2. Click Create publisher block list and give the list a memorable name.
3. Upload your .csv or .txt file by choosing it or dragging and dropping it, then click Upload.
4. Wait while the upload finishes, which Meta says may take a few minutes.
5. Choose where to apply it: all ad accounts, selected ad accounts, or don’t apply to ad accounts now.

Meta says Apply to all ad accounts is hidden unless you have full control of the business portfolio. When someone creates a campaign in Ads Manager, the list is applied automatically to the ad set for the accounts you chose. Meta calls the center the best way to avoid human error if you want a list on every ad. To cover only certain ads, apply the list in Ads Manager instead.

Which level should you apply a list at?

You can apply lists at business, account or campaign level.

• Only people with full control of the business portfolio can apply lists at business level.
• Meta sets a lower limit for the campaign than for the account or business.
• If an error says your ad will not run on certain placements because you exceeded the campaign limit, you might be able to block some entries at account or business level.
• Meta says campaign-level lists are not designed for regular use.

FAQ

Is there a limit on how long a block list can be?

Yes. Meta says a block list cannot contain more than 10,000 lines because of technical constraints, and suggests trying multiple files. Meta also sets a lower limit at campaign level than at account or business level, so if you hit the campaign limit you might be able to block some entries higher up.

Does a block list reach every ad automatically?

Only for the accounts you applied it to. Meta says that when someone creates a campaign in Ads Manager, the list is applied automatically to the ad set for those accounts. If you want it on only certain ads, apply it in Ads Manager instead of through the center.

Can you block content instead of publishers?

Meta offers a separate content block list for that. It helps prevent ads appearing near content you find unsuitable, and it is available through brand safety and suitability Meta business partners. Meta says you can currently see only the lists applied from the center, so ask the partner to review what was blocked.