The Hamming code or Linear block code is used in communication to identify and repair errors. Redundancy bits are introduced to the Hamming communication network (HCN) for error detection and correction. It can detect two errors and correct one error. Quantum-dot Cellular Automata (QCA) is used for designing circuits with high switching speed and low energy dissipation. This work proposes a cost-effective QCA-based (7, 4) Hamming encoder and decoder design. Hamming encoder is designed using coplanar structure and the error detector used in Hamming decoder uses a multilayer structure. The effort is to optimize the area, cost, and energy dissipation. The work proposes a coplanar (7, 4) Hamming encoder and decoder. Hamming decoder is implemented in two parts a syndrome calculator and an error detector. Proposed (7, 4) Hamming encoder circuit reduces cell count by 49.47% compared to [