It's also assumed that the regular workers commonly work in the office because the nengajo may be addressed to a certain family member, or that it may have an address indication in an old system or the old address of a resident who has recently moved.
また、年賀状の区分整理も家族の名前で来ることや住居表示前の旧住所で届くこと、あるいは転居前の住所で届く年賀状も多い事から本務者が内勤をすることが多いと思われる。