18mo training is unusual in 2026. Most pediatricians say 2.5-3.5. Wait for readiness signs - hiding to poo, dry for 2+ hours, telling you about dirty nappy.

Boys often later than girls. 3 was the magic number for mine.

Pull-ups can actually delay because they feel too much like nappies. Switching to knickers/pants helped us when she was ready.

Oh Crap method at 2y9m worked brilliantly. Don't push it before they're ready.