The urea oxidation reaction (UOR) offers an energetically favorable alternative to the oxygen evolution reaction for alkaline hydrogen production and wastewater remediation. However, developing efficient UOR electrocatalysts remains challenging because conventional highly crystalline transition-metal hydroxides often suffer from structural rigidity, which restricts the dynamic surface reconstruction necessary for this complex multistep process. To address this structural limitation, herein, we report a trimetallic CoNiCu carbonate hydroxide catalyst grown directly on carbon cloth (CC) and featuring a stacked nanorod architecture that provides abundant defect sites favorable to deliver a low UOR potential of 1.43 V at 10 mA cm(-2) in 1.0 M KOH containing 0.33 M urea. Post-UOR X-ray photoelectron spectroscopy confirms that the trimetallic carbonate hydroxide transforms into catalytically active Co/Ni oxyhydroxide species. Cu incorporation modulates the electronic structure and facilitates urea adsorption and oxidation. The enhanced UOR activity is due to the synergistic effects of structurally disordered framework, multimetallic electronic coupling, and dynamic surface reconstruction. This work highlights the importance of trace copper incorporation in breaking the structural rigidity of hydroxide-based electrocatalysts, providing insights for developing efficient UOR anodes.