Persoonlijke accountinstellingen, beveiliging en privacy beheren in Outlook.com
Disclaimer: I noticed that the locale is set to nl-NL, while your request was submitted in English. To ensure consistency and clarity, I will continue responding in English.
I understand the deadlock you are facing. Since both accounts depend on each other for verification, you will need to recover one of them using a third working email address, not Account A or Account B.
Please run the Microsoft account Sign-in Helper for Account B first, as you still know its password. If it directs you to the recovery form, provide another accessible email address for Microsoft’s reply and complete the form from a familiar device and location. Include old passwords, exact email subject lines, contacts, and details of any Microsoft services linked to the account.
If the form is rejected, you may submit it again with additional accurate information, up to two times per day. However, support agents and forum contributors cannot manually reset the password, change the registered recovery address, or bypass account verification. Help with the Microsoft account recovery form
Also check any old phones, computers, browsers, or password managers where either account may still be signed in or where the password may have been saved. Do not sign out of any device that still has access.
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