Kaji was 12 months. The only reason I let him sleep with me was because he was recovering from his neuter. He looked so pitiful and he wouldn't settle down unless he was with me. He's been sleeping with me ever since.
My only suggestion would be take him to potty right before bed, and immediately when you wake up. If you get up to potty during the night, take him out too. The more opportunities you give them to get it right, the less of a chance there is for them to get it wrong.