Parents are being forced to foot the bill because of funding cuts, a recent survey suggests.
According to the survey, conducted by the Association of Teachers and Lecturers (ATL), parents are being asked to pay for textbooks, art materials and to buy tickets for school plays and sports events in an attempt by schools to bridge the funding gap.
It also found one in six parents are being asked for cash to help with the running of their children’s schools.
The survey, which questioned almost 1,200 members of the National Union of Teachers (NUT) and the ATL, found three in four (76 per cent) said their school's budget has been cut this year, compared to last, while 93 per cent said they are pessimistic about their school's funding over the coming three years.
Most of the 17 per cent who were asked for money said the amount was not specified but 14 people said it was more than £20 a month.
Around half (49 per cent) of union members said their school had asked parents to pay for specific items.
A London teaching assistant said: "To save money children are often asked to take photos of homework (assignments) on their mobiles."
ATL general secretary Dr Mary Bousted said: "The Government needs to sit up and listen. Schools are already struggling to make ends meet and children are already losing out.
"But Government underfunding means this will get much worse, since in two years' time schools will have to make savings of more than £3 billion a year.
"Unless the Government finds more money for schools and fast, today's schoolchildren will have severely limited choices at school and children from poorer families will be even further disadvantaged because their parents may struggle to provide the resources schools can no longer afford."
A Department for Education spokeswoman said: "The Government has protected the core schools budget in real terms since 2010, with school funding at its highest level on record at almost £41 billion in 2017-18 - and that is set to rise, as pupil numbers rise over the next two years, to £42 billion by 2019-20.
"We recognise that schools are facing cost pressures, which is why we will continue to provide support to help them use their funding in cost effective ways and make efficiencies.
"This includes improving the way they buy goods and services and our recently published School Buying Strategy is designed to help schools save over £1bn a year by 2019-20 on non-staff spend."