Investigations by the Council's Counter Fraud and Investigation Team have resulted in six grammar school offers being withdrawn after applicants were found not to be resident in the city.
Those who had initially been offered the places had claimed to be residents of Southend-on-Sea.
The findings are included in a report due to be considered by the Audit and Governance Committee on 19 October 2026.
The report states that the withdrawn offers freed those places for children who are resident in the city.
The cases related to places offered for the 2026/27 academic year and predominantly involved the boys' grammar schools, with cases split broadly between Westcliff High School for Boys and Southend High School for Boys, alongside one case relating to a girls' grammar school.
Cllr Chris Webster, Cabinet Member for Technology, Learning and Customer Services, said: "Southend school places should benefit Southend children. These investigations help ensure places are available to children who are resident in the city and that the admissions process always remains fair."
The full report will be considered by the Audit and Governance Committee on 19 October 2026 (item 11).