Like his renowned British tenor predecessors Sims Reeves and Edward Lloyd, Coates had a famously protective wife. Moore refers to Coates' home life as serene, with an adorable spouse, sons and daughters; but he thought, despite Coates's good humour, he was not a happy person because he was too much of a worrier. Coates developed financial headaches, too. He wasted a good deal of money in a legal case that he launched against the Performing Right Society, in which he argued that he should not have to pay a royalty to perform music in public which had been brought to him in manuscript, and which therefore, by agreeing to sing it, Coates had encouraged the publishers to publish. He lost the case, and it preyed on his mind and finances for long after, though he refused offers of financial support from other singers. In his last years he thought of going back on the stage and started to slim, but he was seized with anaemia and became permanently confined to bed, frustrated at being unable to assist his country as the Second World War took hold. In July 1940, Gerald Moore presented a half-hour broadcast in tribute to their work together, and received a last letter from him in friendship and gratitude.