http://www.outsidethebeltway.com/501c4-vs-501c3-vs-527/
While all of these organizations, the 501(c)3, the 501(c)4, and the 527, are tax-exempt, each is bound by different rules. Here are the most important differences to understand for the current situation:
Characteristics |
501(c)3 |
501(c)4 |
527 |
Ability to engage in politics
|
Not supposed to engage in any political activities, though some voter registration activities are permitted |
May engage in political activities, as long as these activities do not become their primary purpose |
Politics is what 527s are *required* to do |
Endorsing Candidates
|
CANNOT Endorse Candidates |
CAN Endorse Candidates |
CAN Endorse AND Field Candidates |
Campaign Spending
|
Prohibited |
Permitted but taxed |
Required |
Lobbying
|
Some lobbying |
Substantial lobbying |
No direct lobbying |
General Political Advocacy (not related to legislation or the election of candidates.)
|
Yes, as an educational activity.) |
Yes, provided it is not the primary activity of the organization |
Yes |
Contributions
|
Able to accept unlimited, tax-deductible donations |
Able to accept unlimited, non tax-deductible donations |
Able to accept limited (based on FEC regulations), non tax- deductible donations. |
Donor Reporting
|
Donors kept anonymous. |
Donors kept anonymous. |
Donors are publicly reported. |
Must apply with the IRS
|
YES |
NO |
YES |
The TIGTA IRS audit defines lobbying as: “[A]ttempts to influence specific legislation |