Ah, yes — this is one of those painful surprises when transferring a Facebook Page between Business Managers.
Unfortunately, once you move a Page to a new Business Manager:
You lose access to any ad performance data that was tied to the original ad account(s) unless those ad accounts were also transferred or shared.
Meta does not carry over ad history from one Business Manager to another, because ad data is tied to the ad account, not the Page itself.
Here's what you can do (if you still need the data):
1. Access the original ad account (if possible)
If the old Business Manager and ad account still exist:
Even if you no longer own the Page, you can still view old ad performance (just can’t run new ads with that Page unless it’s re-assigned).
2. Request access to the old ad account in your new Business Manager
If the old ad account isn’t under your current BM, and you want continued access:
Go to Business Settings → Ad Accounts → Request Access
Use the ad account ID from the previous setup
You’ll need someone with admin rights on that account to approve
3. Export historical reports before making future transfers
Not helpful now, but for next time — always export reports from Ads Manager before detaching a Page from its original ad account or Business Manager. That way, you retain the data in a CSV or PDF for future reference or comparisons.
Pro tip for next time:
Instead of transferring the Page, it’s often better to grant partner access to another Business Manager using "Assign Partner" in Business Settings. That way, you retain all ad data and still give another team or agency access without breaking the history.
