20 Pesos

The Banco de Buenos Ayres was the first bank established in what would become Argentina, founded in 1822 under Bernardino Rivadavia's administration. It operated on a fractional reserve model almost immediately strained by the costs of the Cisplatine War against Brazil, and by 1826 the bank had suspended specie payments — meaning notes of this series circulated without any effective metallic backing. They traded at steep discounts against hard currency throughout their brief life.

The bank was liquidated in 1836. Most of its paper was retired and destroyed in the winding-up process, and surviving examples from the 1827–28 period are genuinely rare.