https://get-information-schools.service.gov.uk
Formerly called "EduBase", and currently in CSV format, updated daily.
Data from GIAS can be made available through the DSI API upon request.
Query data in browser:
https://get-information-schools.service.gov.uk/Establishments/Establishment/Details/136899
Download data:
Use date format YYMMDD for example 20210812
edubasealldataYYMMDD.csv
https://ea-edubase-api-prod.azurewebsites.net/edubase/downloads/public/edubasealldata20210812.csv