Abstract Thermally latent curing agents are essential for one-component epoxy systems, enabling long pot life while maintaining high reactivity upon activation. However, strategies for imparting thermal latency to highly reactive tertiary amines remain limited. Herein, we propose a simple and novel approach based on betaine formation between tertiary amines and acrylic acid. This strategy effectively suppresses amine nucleophilicity under ambient conditions while regenerating the active tertiary amine via thermal decomposition during heating. The decomposition behavior was analyzed by 1H-NMR spectroscopy, confirming controlled activation upon heating. The resulting one-component epoxy systems exhibited efficient bulk curing and suitability for adhesive applications. This work provides a versatile and previously underexplored platform for designing thermally latent tertiary-amine curing agents.