To be eligible for a place in Year 7 at one of Lincolnshire's grammar schools, children must demonstrate that they have reached the required standard for entry as determined by 11 plus testing. The tests are normally taken early in the last year of primary school (Year 6).

The Lincolnshire Consortium of Grammar Schools was created to coordinate Testing arrangements across the county. Currently, 13 out of the 14 grammar schools, together with King Edward's VI Humanities College in Spilsby, which is a bilateral school, belong to the Consortium and follow the same Testing arrangements. Caistor Grammar School does not belong to the Consortium and administers its own tests.

Parents who would like their children to take the 11 Plus will need to register for testing towards the end of Year 5.

Because the tests are taken in September, most parents will be able to find out whether their children are eligible for a grammar school place before having to complete the Local Authority application forms.