Estimates of the number of North Koreans overseas vary considerably. Some researchers, as well as a 2015
report by the UN Special Rapporteur on North Korean Human Rights, cite roughly 50,000 overseas workers. Other analysts have given
larger estimates, ranging as high as 120,000 overseas workers. A
fact sheet published by the U.S. Mission to the UN in 2017 cites 100,000 overseas workers, bringing in revenue of over $500 million annually.
The reason for this variation hinges mostly on the difficulty of estimating the number of North Korean workers in China. The number of North Koreans legally entering China has increased significantly in recent years, with over 188,000 reported entrants in 2015, including 94,000 entrants identifed as "workers and crew". This may be connected to a
reported 2012 informal agreement between Beijing and Pyongyang allowing for an increased number of North Koreans to work in China. However, data on the number of reported entrants does not necessarily reflect the total number of North Korean workers in China. On the one hand, some North Korean workers may have been placed in entry categories other than "workers and crew," and workers might stay longer than one-year periods. One the other hand, it is not clear whether the "worker and crew" category includes transportation workers who may enter China on a routine basis for very short terms, or how often North Korean workers (particularly those stationed in the border area) travel back and forth across the border -- in either case, any given worker would be counted as an "entrant" multiple times in a single year.