20 Leva Foreign Exchange Certificate

Bulgaria's foreign exchange certificates — "чекове" in local parlance — were instruments of the parallel currency system operated through Corecom, the state hard-currency retail network. Tourists and Bulgarians receiving remittances from abroad were obliged to exchange hard currency into these certificates at official rates, then spend them at Corecom shops stocked with goods unavailable in the regular socialist economy. The arrangement funneled foreign exchange directly back to the state while rationing access to Western imports by denomination.

By 1986 the system was well into its late-period phase; Zhivkov's government had run it since the early 1960s. These certificates were non-negotiable outside the Corecom network and officially non-transferable, though a secondary black market for them operated openly enough to be an open secret.