50 Pesos

The Banco de Buenos Ayres was founded in 1822 as Argentina's first bank of issue, backed initially by British merchant capital and operating under the government of Buenos Aires province. By 1826, the institution had been absorbed into the newly created Banco Nacional, making notes dated 1827–1828 a transitional curiosity — issued under the old name while the institutional structure beneath it was already being dismantled.

The bank's paper circulation collapsed badly during the Cisplatine War financial strain, and convertibility was suspended in 1826, never fully restored. These late emissions circulated as inconvertible currency in a market that had largely stopped trusting them.