Abstract: Pseudorange observations of Global Navigation Satellite System (GNSS) are well known to be affected by receiver differential code biases (DCBs), which need to be precisely calibrated for pseudo-range-based ionospheric sensing. It is therefore of importance to ascertain the intrinsic characteristics of receiver DCBs in the context of new-generation GNSS based on Global Positioning System (GPS), BeiDou satellite navigation system (BDS) and Galileo. In this contribution, we present a method that enables time-wise retrieval of between-receiver DCBs (BR-DCBs) from code measurements collected by a zero-baseline setup. Based on dual frequency measurements collected in 2013 by four receivers, we conclude that the variation of BR-DCBs may be affected by three factors, namely, the version update of the receiver's firmware, the observation conditions caused by the disassembly of individual receivers, and errors in the estimation method.