Depending on what you've already done in MySchools, you can start adding a school by...
Clicking on "No data available in the table'

OR Clicking on an empty row. (It will be super thin.)

OR Clicking on the row of any school already in the shortlist.

Next, click ‘+New entry’.

Then click ‘Nothing Selected’

In the dropdown that appears, click the school you want to add.. You can type in the first letter to jump to that section of the list.

To add another school immediately, click ‘Apply and add new.’ Otherwise click OK.
