KS4: there's no requirement for pupils to do it
Work experience is not statutory for pupils under 16 in maintained schools or academies. The DfE told us this.
The duty to provide a standard amount of 'work-related learning' at Key Stage (KS) 4 was removed in September 2012, in line with recommendation 21 of the Wolf report (see page 8).
KS5: work experience is expected
This is explained in the work experience section of the non-statutory guidance from the DfE on