Replacing Admob ad unit IDs
more info here.
Apps you previously monetised in legacy AdMob used legacy Publisher
IDs to identify the ad units and legacy Mediation IDs for mediation.
Both of these IDs have been replaced by a single new ad unit ID. To
benefit from all of AdMob's mediation features, you need to update the
legacy IDs in each of the ad units in your apps to their corresponding
new ad unit IDs, then republish your apps.
Update your ad unit IDs
To update your app's legacy Publisher and Mediation IDs to the new ad unit IDs:
- Download your ad unit ID mappings as a .CSV file.
- Go to Account > Legacy AdMob data.
- Click the Download button to download a .CSV file of your legacy Publisher and Mediation IDs mapped to your new ad unit IDs.
- Open the .CSV file and use the mappings to replace each of the
legacy Publisher and Mediation IDs in your app with the corresponding
new ad unit IDs.
- Publish your app containing the new ad unit IDs.
You may want to wait to publish until your next scheduled app release
if you're still actively developing the app. However, please note that,
to benefit from all of AdMob's mediation features you need to update
and republish the app using the new ad unit IDs.