In the current digital era, there is a need of secure and efficient nano communication systems with ultra‐low power consumption. One technology that can be used for designing these systems is quantum‐dot cellular automata (QCA). In the nano regime, QCA is able to operate with higher speed and lower power dissipation along with high density compared to CMOS technology. This work explores the applicability and feasibility of designing nano communication systems using code converters. In this paper, efficient 4‐bit, 8‐bit, and 16‐bit designs of binary to gray (B2G) and gray to binary (G2B) converters which can be scaled up to N‐bits are proposed. The N‐bit B2G and G2B converters can be designed using 33 + 38 (0.25N − 1) and 63 + 76 (0.25N − 1) cells with a latency of 0.5 and 0.25N clock cycles, respectively. The converters are then used to design 4‐bit, 8‐bit, 16‐bit, and 32‐bit communication systems for efficient data transmission and reception. Based on the performance comparison, it is observed that the proposed B2G and G2B designs achieve up to 90.03% and 99.64% improvement in terms of cost of the circuit thereby making them most cost efficient QCA designs. In addition to this, exhaustive energy dissipation analysis of the proposed designs is also presented. It is observed that the proposed designs can be efficiently utilized in designing nano communication systems requiring minimal area and ultra‐low power consumption.