England's largest education union has accused the government of breaking a pledge that every school would get "at least a small cash increase".
The NEU teaching union based its claim on figures published by the DfE last month.
The union compared the schools block funding allocations for 2017-18 with the school block funding allocations plus the new teacher pay grant for 2018-19.
It said that 4,819 schools had received no cash increase, or had seen their funding fall. The union said this included a quarter of primaries and one in six (17 per cent) of secondaries.
Last March, education secretary Damian Hinds told MPs: “With the national funding formula, each school will see at least a small cash increase.”
And two months later, prime minister Theresa May told the Commons that “the new national funding formula is providing for a cash increase for every school in every region”.
Kevin Courtney, joint general secretary of the NEU, said: “This is yet another failure and another broken promise by government on school funding.
“The fact remains that schools were never going to manage on the money promised by government. However, head teachers, teachers, school staff and parents will be dismayed that even the meagre amounts of funds supposedly allocated to schools will not be received by everyone.
“Parents and school staff simply cannot trust what the government says on education funding.”
A Department for Education spokesperson said: “Since 2017, we have given every local authority more money for every pupil in every school to make funding fairer across the country.
“Government provides this money to local authorities and they have the freedom to work with schools to allocate their budgets in a way that best suits local needs. It is also important to recognise that schools receive other sources of funding - such as the additional Teachers’ Pay Grant worth £187m this year.
“While there is more money going into our schools than ever before, we do recognise the budgeting challenges schools face and that we are asking them to do more. That’s why we’re supporting schools and head teachers, and their local authorities, to make the most of every pound.”