Microsoft 365 Customer Service and Support Assistance for billing and subscription management issues is available online business signs near me or by telephone during China business hours (Beijing Time), Monday through Friday. Billing and subscription management support can be accessed using the same phone number and online service request process as with technical support. The support telephone number can be found on the Microsoft 365 operated by 21Vianet portal. 2 Severity A is only available to customers who signed an advanced online service agreement with 21Vianet through a sales account manager. For billing and subscription management support, the highest severity level is B. Presales support for Microsoft 365 operated by 21Vianet provides assistance on subscription features and benefits, plan comparisons, pricing and licensing, and helps to identify the right solution to meet your business needs. Presales support can be accessed using the same phone number as with technical support. You must have at least one subscription bought through Microsoft to access Microsoft support. Billing and subscription management support can be accessed using the same phone number and online service request process as with technical support. If you contact us from a number that isn't registered with your organization profile, the Microsoft support representative sends a verification code to the registered email or phone number in your Microsoft 365 admin center profile.