To qualify for nonprofit donations and discounts, you must hold recognized charitable status in your country and sign Microsoft’s non-discrimination policy. Microsoft reserves the right to verify eligibility at any time and to suspend the service for ineligible organizations.

Small & Mid-sized nonprofits - Microsoft 365 Business Basic and Standard Comparison

Large nonprofits - Office 365 E1, E3 and E5 Comparison 

All plans include:

• Guaranteed 99.9% uptime, financially backed service level agreement
• IT-Level web support and 24/7 phone support for critical issues
• Active Directory integration to easily manage user credentials and permissions
• World- class data security

Source: Microsoft.com