Parents are being urged to choose the schools they would prefer their children to attend in September before the cut-off point.
The national deadline for parents - including those in Middlesbrough - to return their Primary School Preference forms is Wednesday, January 15.
More than 1,900 preference information packs were originally sent out in November to nursery age pupils born between September 1, 2015 and August 31, 2016 living in Middlesbrough, but over 250 remain outstanding despite recent reminders being sent out by the School Admissions Service.
If preference forms are returned after the closing date, they will not be considered until all the 'on-time' applications have been processed.
Where preference forms are not returned at all, children will be allocated places by the Council at a school with places remaining after all the other applications have been processed.