What is the insubstantial part test?
The insubstantial part test is the default applied to all 501(c)(3) organizations. Under this test, the organization may engage in lobbying as long as it is not a substantial part of the organization’s overall activities. This test is vague and gives the IRS the authority to decide what activities constitute lobbying and how much lobbying is acceptable. Nonprofits can lose tax-exempt status if conducting more than an “insubstantial” amount of lobbying.
