Northern Ireland's education minister has intervened to try and prevent parents from paying tax on private school fees from January.
Paul Givan said fee-paying schools were different in Northern Ireland from those in England, and should not be subject to value-added tax (VAT).
The standard VAT rate of 20% will be added to private school fees from 1 January 2025, which the government says will help fund more teachers' salaries in England.
About 2,500 pupils in Northern Ireland attend grammar school preps, Christian and other independent schools.
Their parents face paying more for their children's education as the government plans to remove a long-standing VAT exemption for private schools and independent schools.
While some famous private schools like Eton and Harrow in England charge about £50,000 a year, schools in Northern Ireland charge parents a lot less than that.
Mr Givan told BBC News NI that schools in Northern Ireland could not be directly compared with many private schools in England, and the new UK-wise approach did not "reflect how the Northern Ireland education system is funded".
While education is devolved to the Northern Ireland Assembly at Stormont, taxation is decided at Westminster.
"This is ultimately HMRC, it's the Treasury and I'm making the representation on behalf of schools in Northern Ireland and parents as to why they shouldn't be included," Democratic Unionist Party (DUP) minister Mr Givan said.
"I recognise the real concerns parents have."
In a statement to BBC News NI a government spokesperson said: "We want to ensure all children have the best chance in life to succeed."
"Ending tax breaks on private schools will help to raise the revenue needed to fund our education priorities for next year."
Independent Christian schools in Northern Ireland are among those affected by the VAT changes.
There are nine independent Christian schools in Northern Ireland, including five run by the Free Presbyterian Church.
'By no means are many of our parents rich'
The Reverend Brian McClung is the administrator of Newtownabbey Independent Christian School on the outskirts of Glengormley in County Antrim.
He told BBC News NI the VAT changes could lead to parents paying more in fees.
"Our parents pay less than £2,000 a year to send a child to our school as they want the education we can provide," he said.
"We already fundraise to cover the total cost of running the school so that we can keep fees affordable, but we would have no option but to charge parents more.
"We have some pupils in our Christian schools who are entitled to free school meals, so by no means are many of our parents rich."
"For instance, some families go without holidays to send their children to our schools and I know that some grandparents of children help out to pay the school fees."
"We are hoping that the Treasury understands that we just can't be compared with better-resourced private schools in England."
The Holywood Steiner School, which has more than 170 pupils, also faces charging parents more.
Steiner education focuses on childhood development and imaginative play instead of testing, influenced by the work of philosopher Rudolf Steiner.
'Increase could be daunting'
The principal of the Steiner school, Peter Chambers, said the school was almost completely funded by the fees parents paid.
"The education children get in our school, we believe, is very holistic and is based around child development, as opposed to excessive amounts of testing," he said.
"Our top end fee is just over £6,000 a year so it could be an additional 20% on top of that."
"And to have all these changes implemented in January becomes very complex for school budgets."
Mr Chambers said he was also concerned that a rise could make the school unaffordable for some parents.
"To have a mid-year 20% increase for families could be a bit daunting," he said.
A number of grammar schools may also face raising fees, including those with prep departments for younger children.
Twelve grammars have prep departments, while three admit boarding students, whose families also pay fees.
About 1,500 pupils in Northern Ireland went to grammar preps in 2023-24.
'Just not the same' as England
Stephen Moore, the principal of Friends' School in Lisburn, which has a prep department said the schools were not the same as independent schools in England.
"They are entirely self-financing and have much greater autonomy in how they're run than we do," he told BBC News NI.
"It's legislation that's not really intended to capture schools like prep schools in Northern Ireland which do receive funding from government and which are very much departments of local grammar schools.
"It also could have an impact on the sustainability of prep schools here and that could also have a knock-on effect on the grammar schools of which they're an integral part."