Five year olds who start school begin as a Year 0 or Year 1 (formerly Primer 1 or J1) and progress each year to Year 13 (formerly 7th Form). Most children in Year 0-8 will be aged between 5 and 12 years old.
If your child starts school in the second half of the year, and is aged between five and six, they will be classed as Year 0. If they start school in the first half of the year they will be classed as Year 1.