Hello @Toby Kernon,
Welcome to Microsoft Q&A Forum!
Could you please help me confirm whether there is another active Global Administrator in your organization? If there is, that person should be able to reset your password through the Microsoft 365 admin center. This is usually the quickest way to recover access, as Global Administrators have full permission to manage users, roles, and sign-in details.
If another Global Administrator is available, please share the following Microsoft article with them, as it provides detailed step-by-step guidance on how to manage admin access and reset passwords: Reset passwords - Microsoft 365 admin | Microsoft Learn
If you are the only admin:
You will need to contact Microsoft’s Data Protection team. This team has the authority and the specific security procedures to verify your identity as the legitimate owner of the account from their end. Please try to find the related hotline number to call the frontline and let them raise a ticket for you: Customer service phone numbers - Microsoft Support
(When you call the support number, you may hear an introduction of about 30 seconds such as "you can visit the link...". You can ignore this introduction and wait until you are presented with the options. Then press "1" as a business email user, and again "1" for technical help.)
I hope the information provided helps guide you in the right direction. If you encounter any difficulties during the call or are unable to reach an agent, please update me so that I can look for another alternative way to assist you.
Warm regards,
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