Parents in Brighton and Hove must get their primary school applications to the city council by Sunday, January 15.
The deadline is for children due to start primary, infant and junior schools in September 2017.
This applies to children born between 1 September 2012 and 31 August 2013 for reception places, and for children born between 1 September 2009 and 31 August 2010 for Year 3 junior school places.
Brighton and Hove City Council said missing the deadline increases the risk of children not being offered a place at one of their preferred schools – even if they have a sibling at the school.
To apply online, visit: www.brighton-hove.gov.uk/schooladmissions
Parents who do not wish to apply online should contact the council’s school admissions team at email@example.com or on 01273 293653 for a hard copy of the application pack. Parents who feel they need extra help with the admissions process – perhaps because English is not their first language or they have only just moved to the city – can phone 01273 290355 for impartial support.