20 Patacas Banco Nacional Ultramarino

The Banco Nacional Ultramarino, originally chartered in Lisbon in 1864, had long been the note-issuing authority for Portuguese overseas territories. By the time this series entered circulation, BNU's role in Macau was purely residual — the Autoridade Monetária de Macau had overseen monetary policy since the 1989 handover preparations, and BNU continued issuing pataca notes only under a formal concession arrangement that survived the 1999 transfer of sovereignty to the PRC.

The pataca itself is pegged to the Hong Kong dollar at a fixed rate of 1.03 HKD, a relationship that has held without interruption since 1977.