Can't create new Service Principals in Azure despite being under quota

Question

I can't create any new SPs in Azure despite being under quota. If I run:

 az ad sp create-for-rbac

I get

 The directory object quota limit for the Principal has been exceeded. Please ask your administrator to increase the quota limit or delete objects to reduce the used quota.

When I do this:

 az ad sp list --show-mine | grep objectId | wc -l

or this

 az ad app list --show-mine | grep displayName | wc -l

It shows that I don't own many applications/service principals (the default limit is 250.)

Answer 1

It turns out the Azure has a secret "Recycle Bin" for applications!

I did the following to empty this recycle bin

Install-Module -Name AzureAd -AllowClobber -Scope CurrentUser

Get-AzureADDeletedApplication -all 1 | ForEach-Object { Remove-AzureADdeletedApplication -ObjectId $_.ObjectId  }

This will permanently remove all deleted applications (that you owned.) If you want to be more selective then run:

Get-AzureADDeletedApplication -all 1 

And go through every app deleting it like this:

Remove-AzureADdeletedApplication -ObjectId 00000000-0000-0000-0000-000000000000