This paper presents the four primary reasons why any population may be hard to count (HTC), four broad strategies for successfully addressing those challenges, and guidance on specific populations which have historically been HTC across national contexts. In doing so, it will help to produce higher quality census data and a culture in which those hardest to reach are prioritized.

This technical note is part of a series on Select Topics in International Censuses, exploring matters of interest to the international statistical community.

This paper provides information on internationally recognized standards on special procedures and protocols for the archiving and preservation of individual census records.

This technical note is part of a series on Select Topics in International Censuses, exploring matters of interest to the international statistical community.