The Pupil Premium was introduced in April 2011 and is additional funding that the government gives to schools for each pupil on roll where they are deemed to be disadvantaged. The money must be spent on that pupil to support their education, but it is for the school to determine how it is spent. The Department of Education website is a good source of additional information:
The Pupil Premium for the financial year 2016 - 2017 is £1320 per child and for Looked After children is £1900 per child. This is significant additional money for schools to spend on supporting disadvantaged pupils and schools are very keen to ensure that all eligible pupils are ‘signed up’. Grants are based on those pupils included in the January schools’ census.