Nonprofit organizations must meet certain requirements set by the Internal Revenue Service (IRS) to maintain their tax-exempt status. These requirements include:

• Filing the appropriate tax forms annually: Nonprofits must file Form 990 or one of its variations, depending on their gross receipts and other factors.
• Being organized and operated exclusively for tax-exempt purposes: Nonprofits must have a stated purpose that falls within one of the categories outlined by the IRS, such as charitable, educational, or religious.
• Prohibiting private inurement and excessive benefit transactions: Nonprofits cannot provide excessive compensation or personal benefits to individuals who are in a position to influence the organization's activities.
• Limiting political activity: Nonprofits cannot engage in partisan political activity or endorse candidates for public office.
• Maintaining accurate and complete records: Nonprofits must keep detailed records of their finances and activities, and make them available for inspection upon request.
• Abiding by state and federal laws: Nonprofits must comply with all applicable laws and regulations governing their activities, including those related to fundraising, employment, and reporting.

Overall, compliance with these requirements is essential for maintaining a nonprofit's tax-exempt status and ensuring that donors can trust that their contributions are being used for charitable purposes.

Generally Accepted Accounting Principles (GAAP) are a set of standards and guidelines for financial accounting used in the United States. Nonprofit organizations are also required to follow GAAP principles to ensure accurate and transparent financial reporting. Some of the key GAAP principles that nonprofits must adhere to include:

• Accrual Accounting: Nonprofits must use accrual accounting, which records income when earned and expenses when incurred, rather than when cash is received or paid.
• Donor Restrictions: Nonprofits must properly account for donor restrictions on contributions, distinguishing between restricted and unrestricted funds, and reporting the use of restricted funds in accordance with donor requirements.
• Net Asset Classification: Nonprofits must classify their net assets as either unrestricted, temporarily restricted, or permanently restricted, based on the nature of the donor restrictions on contributions.
• Financial Statement Presentation: Nonprofits must prepare and present financial statements in accordance with GAAP principles, including a statement of financial position, a statement of activities, a statement of functional expenses, and a statement of cash flows.
• Disclosure Requirements: Nonprofits must disclose information in their financial statements about significant accounting policies, donor restrictions, related-party transactions, and other material information.

Following these GAAP principles can help nonprofit organizations ensure their financial statements are accurate, transparent, and comply with accounting standards. This can help build trust with donors and stakeholders, and support the nonprofit's mission and goals.