The aim of this article is to build, visualize and examine the network structure of transfers processed by ACH Colombia, the financial infrastructure that clears and settles most of the value and number of retail electronic transfers ordered by individuals and firms in Colombia. There is evidence to suggest that ACH Colombia’s networks of transfers differ from those usually documented in the financial network literature: they are dense, homogeneous in the distribution of linkages, and highly reciprocal and transitive. The role of financial institutions as processors of payment orders determines this topology; yet, the distribution of the values transferred is heterogeneous, which relates to the size of financial institutions as measured by their asset value or their number of clients. Results are useful for better understanding the functioning of ACH and other retail payment systems.