The C-Bill (short for ComStar Bill) is the standard form of currency used in the fictional universe of BattleTech. C-Bills make up about 10% of all currency in the Inner Sphere. C-Bills are issued by ComStar, an Earth-based organization that maintains the Inner Sphere's interstellar communications network. Though most business in BattleTech is conducted in the currency of individual states, ComStar's neutrality made its currency the primary medium of exchange for transactions conducted across national boundaries. A single C-Bill has about the same value as three US dollars of the late 1990s.