A shell company or blank check whose securities trade on the over-the-counter bulletin board (OTCBB). Bulletin board shells are usually sought by companies willing to go public through a reverse merger with a public shell. Contrary to pink sheet companies that are almost subject to no reporting requirements, bulletin board companies are required to comply with the rules of the Exchange Act and must be transparent in their operations.

Bulletin board shells are known for short as OTCBB shells.