The Sucre became inconvertible shortly after World War I began in 1914 due to international political tension.

Despite extensive measures to support the Sucre's value, the exchange rate continued to rapidly decline.

Following the suspension of the gold standard on 8 February 1932, foreign exchange controls were adopted on 30 April which fixed the official buying rate at 5.95 per U.S. dollar.

The foreign exchange controls were finally lifted in September, 1937 and the official rate was set at 13.5 sucre per U.S. dollar.

The International Monetary Fund (IMF) established the purchasing power parity of the sucre at 13.5 per USD on 18 December 1946.

The Sucre maintained a fairly stable exchange rate against the U.S. dollar until 1983 when it was devalued to 42 per USD and a crawling peg was adopted.

Depreciation increased rapidly and the Sucre's free market rate was over 800 per USD by 1990 and nearly 3000 by 1995.

Centavo coins minted as denominations of the peso continued to circulate after the introduction of the sucre.

The Banco Central del Ecuador (Spanish: Banco Central del Ecuador Sociedad Anonima) issued provisional notes for 80 centavos and 4 sucres between 1885 and 1887 due to a conversion rate of 5 pesos = 4 sucres for the earlier notes of this bank.

The gold clause was retained on Banco Central's notes until 1939, when the text was modified to Pagará al portador á la vista CINCO SUCRES.

In 1949–1950, Banco Central introduced new notes of reduced size (157 × 68 mm) in denominations of 5, 10, 20, 50 and 100 sucres and dropped the phrase Pagará al portador á la vista, leaving only the literal numerical value of the presidency.

The next change came in 1975, when the back of all circulating notes was redesigned to show the new national coat of arms.

Beginning in 1984, the title Banco Central del Ecuador appears on the notes, without a printer's imprint and without Sociedad Anonima.