This article analyses labour-intensive workforce strategies in Japan's government-run informational infrastructure (post, telegraph, and telephone) and in the adjunct services associated with their administration in the decades up to the Pacific War. It asks to what extent the growing scale of employment in Japan's communications infrastructure in this period confirms the existence of labour-intensive growth outside the manufacturing sector, and how far the growth of the labour force in post and telecommunications was facilitated by specific labour-absorbing institutions—that is, formal or informal institutions designed to mobilise or incentivise large numbers of employees. The discussion of these two associated questions shows not only that this area of infrastructure provision was highly labour-intensive in terms of the numbers employed and the diverse tasks undertaken, but also that the government-run postal system in effect depended for its growth and development on labour strategies and labour-absorbing institutions analogous to those usually associated with manufacturing development. The article also seeks to establish how far we can see in this sector the gradual improvement in the quality of labour normally associated with the labour-intensive industrialisation process, providing evidence that the evolving institutions were closely associated with a gradual improvement in the quality of labour and its ability to interact with rapidly changing needs and technologies.