This is a required check for new staff since the 1st September 2013 to check on appointment that a teacher is not prohibited from teaching.
Until recently this was only for teachers who had qualified teacher status (QTS). This is no longer the case. The check should be done retrospectively, and cover staff who have been appointed since 1 April 2012. Although there is no requirement to retrospectively check teachers who commenced their current employment prior to that date it would still be prudent to do so.
It is a separate check from the DBS and Children's Barred List check.
To perform this check you must use the Employer Access Service on Teacherservices - a database that is maintained by the NCTL, the National College for Teaching and Leadership.
Since 1st April 2018, the NCTL has been replaced by the Teacher Regulation Agency
Please see Paragraph 116 in the DfE Guidance.