Head-on collision of collisionless two-dimensional, unmagnetized plasma made up of positrons, hot electrons and cold ions have been considered for investigation. Ion-acoustic Kadomtsev-Petviashvili (IAKP) solitons are derived using the extended Poincar \(\acute{e}\) -Lighthill-Kuo technique to study soliton solutions, trajectories, and phase shift. Factors such as density ratio, temperature ratio, and reference frame’s velocity significantly impact phase shift. The study reveals that phase shift decreases with the density ratio and temperature ratio but increases with the reference frame’s velocity. Phase shift also raises for an increase in the electron density and the positron temperature. We also studied special solutions for different time evaluations of the head-on collision. The combined framework forms in the interaction zone, rising and declining over time. As per our knowledge, head-on collision of solitons in the framework of the KP equation till now have not been studied. The results of this work may be valuable for understanding the collective processes connected with IAKP solitons colliding, which is beneficial in astrophysical conditions and laboratory plasma.
