Generated by Office Copilot:
I spent over an hour with Chat support and he could not get me out of this issue even though I shared this exact information. Title was generated by Office Copilot. I confirmed the phantom device is visible on my iPad (IOS): Device protection->Other devices->
What to tell the agent (so you don’t get bounced)
Use this exact wording:
“Microsoft Defender for iOS says ‘This account has reached its devices limit’ even though no devices appear in my Microsoft account. My old iPhone was erased while Defender was still signed in. I need my Defender mobile device enrollment reset.”
Why this works when everything else doesn’t
The issue isn’t on your devices or in your account UI — it’s a server-side Defender mobile quota flag that only Microsoft support can clear. The consumer Defender team (under Microsoft 365 support) is the only group with access to that system.