Hi Gaël Varlet,
Thank you for reaching out to us on the Microsoft Q&A forum.
By Signing up for a trial or paid subscription, which automatically creates Microsoft 365 tenant.
If you need to set up a new Developer Program account, for example to use a different email account or account type, you must delete your existing account first if it already exists. You can only have one Microsoft 365 Developer Program account associated with your phone number. To delete your account, sign in to your dashboard and choose Delete Profile.
Before requesting a developer subscription, ensure that you have joined the Microsoft 365 Developer Program directly or through Visual Studio Professional or Enterprise (if you’re a subscriber). If you qualify for a Microsoft 365 E5 subscription through the developer program, the subscription setup flow should start automatically after you join the program.
Eligible for Microsoft 365 Developer Program:
- Microsoft account (created by you for personal use)
- Work account (issued by an admin for business use)
- Visual Studio ID (created for your Visual Studio Professional or Enterprise subscriptions)
Your Microsoft 365 E5 developer subscription is strictly for development purposes only. Any use beyond development may result in revocation. Kindly note that commercial transactions (such as purchasing paid services) are not currently supported within the developer sandbox subscription.
Please follow URL for detailed process of Microsoft 365 developer sandbox setup subscription:
Set up a Microsoft 365 developer sandbox subscription | Microsoft Learn
Join the Microsoft 365 developer program with following link:
https://developer.microsoft.com/en-us/microsoft-365/dev-program
Please don't hesitate to reach out to us if you have any further queries.
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Thank you.