Unable to provision Microsoft 365 E5 Instant Sandbox.

Try these supported steps for this exact billing-account dropdown issue:

1. In the sandbox setup page, select the Refresh (↻) icon next to Billing account.
2. Wait a few seconds after billing account creation, then refresh again. The billing account can take a short time to appear.
3. If it still shows No billing accounts found, try creating a new billing account.
4. If the portal shows BillingAccountAlreadyExists or says Your billing account is ready but the account still does not appear, check whether the account has no Azure plan enabled.
5. If there is no Azure plan on that account, create an invoice section. This action may provision the required Azure plan. After the invoice section is created and the Azure plan is available, retry sandbox setup.
6. If there is an agreement not signed error, sign the agreement in the Microsoft Admin Center. During that flow, the required billing profile and invoice section also need to be created. Then retry the operation.
7. When the billing account finally appears, confirm that Billing account, Billing profile, and Invoice section all have values selected. The Set up button stays unavailable until all three are populated.
8. If provisioning starts but takes unusually long, refresh the Developer Program dashboard. If it still does not complete, contact Microsoft 365 Developer Program support.

Relevant sign-in detail for this scenario: the Developer Program dashboard uses the member ID used to join the program, while the sandbox itself uses the administrator ID created during sandbox setup.

• Set up a Microsoft 365 developer sandbox subscription
• Set up a Microsoft 365 developer sandbox subscription
• Microsoft 365 Developer Program FAQ