I guess it's partly this; partly also the issue is that various USD emissions can vary visually a lot - it's probably also easier for the FX workers to just lea

I guess it's partly this; partly also the issue is that various USD emissions can vary visually a lot - it's probably also easier for the FX workers to just learn the most recent form and not dozens of them? AFAIK the 2012+ dollars are "travel-safe". Same for EUR. The 2002 emission is entirely different visually than the 2013 one. [1] On my trip to Central Asia last year I had a mix and the old ones were not accepted in the bank. On top of all that, it's generally best to have flawless banknotes. Ones worn out, with marks etc. are either not accepted, or accepted with a discount in some places. [1] https://en.wikipedia.org/wiki/Euro_banknotes https://en.wikipedia.org/wiki/Euro_banknotes