Children are entitled to start school in the September after their fourth birthday, meaning parents/carers of children born during the period 1 September 2014 and 31 August 2015 must apply by 15 January 2019.
Essex County Council has warned that any applications submitted after the deadline will only be considered once all on-time applications have been determined.
The council has also encouraged parents to use all four of the preferences available and to check the admissions criteria for each school they wish to apply for to ensure they have the best chance of being offered a preferred place.
Applications can be made online here.
Cllr Ray Gooding, Essex County Council's Cabinet Member for Education, said: “Starting school for the first time is a big milestone in a child's life and it is crucial that applications for school places are received on time to give children and their parents the greatest chance of being considered for a school they want.
“The deadline for applications is 15 January so I would encourage any parents who haven't already applied for their child's reception place to get their application completed over the festive break."