Abstract Previous studies have shown that the average dawn‐dusk component of the perpendicular plasma flow in the plasma sheet ( V ⊥ ) can vary depending on the distance relative to the neutral sheet and the dawn‐dusk component of the interplanetary magnetic field (IMF B y ). In this study, we combined 33 years of data from the Geotail, Time History of Events and Macroscale Interactions during Substorms, Cluster, and magnetospheric multiscale missions to study the slow (<200 km/s) ion flows perpendicular to the magnetic field. We find that IMF B y has a hemispheric dependent influence on both the tail B y and tail V ⊥ . Particularly, the influence is more prominent in the midnight sector (compared to both the pre‐ and post‐midnight sectors) and at distances far from the neutral sheet (compared to the distances close to the neutral sheet). However, at distances close to the neutral sheet, there is an increased dominance of duskward flows which dominates over the systematic influence of IMF B y on tail V ⊥ . Our results indicate that IMF B y has a major influence on the magnetic flux transport in the magnetotail, mainly at distances far from the neutral sheet. The influence is weaker at distances close to the neutral sheet. Plain Language Summary The dawn‐dusk component of the interplanetary magnetic field (IMF B y ) can “penetrate and induce” the magnetic field (of same direction) in the magnetotail's plasma sheet. Consequently, IMF B y can cause a dawn‐dusk asymmetry in the plasma sheet flow. Recently, it has been found that the dawn‐dusk asymmetry of the plasma sheet flow can also depend on the distance with respect to the neutral sheet. These two factors present a competing effect on the dawn‐dusk asymmetry of the plasma sheet flows. In this study, we will analyze these two competing factors (i.e., IMF B y and distance to the neutral sheet) on the plasma sheet flows. We find that IMF B y only has a hemispheric dependent influence on tail V ⊥ at distances far from the neutral sheet. At distances close to the neutral sheet, duskward flows become more dominant and IMF B y does not have a clear influence on tail V ⊥ . Our results indicate that IMF B y has a major influence on the direction of the magnetic flux transport in the magnetotail, only at distances far from the neutral sheet. Key Points IMF B y has a systematic interhemispheric influence on the B y and V ⊥y in the magnetotail's plasma sheet The influences are more prominent in the midnight sectors and at distances far from the neutral sheet At distances close to the neutral sheet, duskward diamagnetic drift dominates over the influence of IMF B y on tail V ⊥y