In 2013, the US Federal Reserve began issuing new banknotes with improved counterfeit protection.
Dollars issued before 2013 are considered old.
Recently, some countries with a high level of dollarization or economic dependence on the United States have begun to abandon the old dollar.
This was reported by the publication Finance Mail, citing Anton Palyulin, a lecturer at the Department of Fundamental Legal and Social-Humanities Disciplines at the Russian University Synergy.
As Palyulin explained, some Caribbean countries, Iran, Zimbabwe and Venezuela do not accept old-style dollars.
Problems with exchanging old dollars may also arise in a number of Eastern European countries, namely Poland, the Czech Republic, Romania, Slovakia and Bulgaria.
These countries use national currencies or euros, and dollars cause doubts or refusals from sellers, Palyulin explained, writes Finance Mail .