The franking privilege is a perk which grants an elected official the right to send mail through the postal system for free, often simply by signing his or her name where the postage stamp would normally be placed.

In theory, elected officials and the postal service are both paid for by the taxpayer. The postal service represents a fixed cost - that is, adding the official's mail to the existing mailstream does not change the postal system's total costs. The franking privilege allows elected officials to send official mail without creating accounting transactions that, at the total government level, will cancel each other out.

In practice, the franking privilege is applied to more than just the official mail necessary for the conduct of the office. Franking is one of the largest advantages of incumbency, contributing to a very high reelection rate in the U.S. legislative branch.

In the United States, members of the House and Senate are allowed this privilege.

Franking can be automated using an autopen.