Bolivia's Ministry of Economy and Public Finance, working with the Central Bank of Bolivia, reaffirmed that Serie B banknotes in BOB 10, BOB 20 and BOB 50 remain fully valid legal tender and continue to circulate normally, and announced an optional mechanism to exchange Serie B notes for Serie A. The authorities linked the measure to recovery operations and controls following the 27 February air accident in which some notes were stolen. The Central Bank indicated that only a marginal share of Serie B notes lack legal value, limited to the stolen notes, which have been identified and permanently invalidated; voluntary returns, seizures by the financial system and Central Bank custody actions were cited as limiting the risk of invalid notes circulating. The optional exchange will be available from 16 March at all financial institutions in the national system and at the Central Bank’s cash offices, with immediate replacement for anyone experiencing acceptance difficulties. The Central Bank also plans to complete the logistical provision of Serie A notes in the same denominations to private banks by Sunday.