A block list is a list of apps, websites or video publishers you upload to Meta so that your ads are never shown on or beside them. It is a brand safety control: a way of saying “not there” about specific places where Meta places ads alongside other people’s content.
How a block list works
Block lists began with the placements where Meta puts ads inside other people’s content: Audience Network, which shows your ads in third-party apps, and in-stream placements, which show them during videos made by publishers and creators. Meta has since extended them to Facebook and Instagram feeds, where a list can name profiles whose posts your ads should not appear next to. Which placements a list covers has changed more than once, so check the brand safety settings for the current scope.
You create the list in the brand safety section of your business portfolio settings, either by pasting domains and app identifiers or by uploading a file. Then you apply it to ad accounts. At the time of writing (October 2026), one list can be applied to several accounts, and Meta screens each placement against it before delivery. To find candidates, you can download Meta’s publisher lists (which show where ads could run) and delivery reports (which show where your ads actually ran).
A block list sits alongside other controls. An inventory filter sets how cautious Meta should be about content themes in general, such as tragedy or mature topics. Topic and content-type exclusions do something similar for in-stream video. A block list is the most precise of these: it names specific publishers rather than broad categories.
Why it matters
Where an ad appears says something about the brand. A UK law firm, a children’s nursery group or a bank would not want its ad showing in a gambling app or next to a video full of conspiracy content, even if the impression was cheap. Low-quality apps can also produce accidental taps that look like clicks but never become customers, which pushes up apparent engagement while doing nothing for sales.
For businesses in regulated sectors, there is a second reason. The ASA and the CAP Code judge an ad partly by where it was seen, and placing certain products in front of the wrong audience can cause a complaint. A block list is not a compliance system in itself, but it helps keep ads away from places that would make one more likely.
Common mistakes
- Uploading a huge generic list found online without checking it, which can block perfectly good placements and shrink delivery.
- Creating a list and never applying it to the ad account that actually runs the campaigns.
- Assuming a block list covers every placement and every kind of content. It only blocks the publishers and profiles named in it, on the placements Meta applies it to.
- Setting it once and forgetting it. New apps appear constantly, so a list needs a periodic review against delivery reports.
- Using a block list to fix poor results that really come from weak creative or the wrong optimisation goal.
How to act on it
First decide whether you need partner placements at all. For many small UK businesses running lead or sales campaigns, turning off Audience Network removes most of the risk in one step, and you can compare results with and without it. If those placements are worth keeping, download the delivery report after a couple of weeks, sort by impressions, and add anything inappropriate or suspiciously click-heavy to a block list.
Keep the list short and specific, name it clearly, apply it to every relevant ad account, and review it every few months. Pair it with a sensible inventory filter and with placement exclusions where a whole placement does not suit you. I check these settings as part of routine Facebook and Instagram ads management, because they are easy to set up and easy to forget.