The schools, a mixture of cathedral schools, former direct grant and some among the elite group of independents in the country, have formed a vanguard looking to take on academy status.
Four independent schools have plans to make the change with more likely to follow, according to the Independent Schools Council.
Geoff Lucas, general secretary of the HMC, which represents the biggest independent schools in the country, said he expected up to six members to become academies.
The HMC will run information sessions on academy status at its conference in October. "We are not encouraging members to become academies. They are independent schools and it is in their nature to make their own decisions," said Mr Lucas. "It is not something that should be done lightly. Taking the Queen's shilling means schools lose some of their independence."
The Girls' Day School Trust said it was holding discussions with six schools and organisations interested in making the move.
And 23 of the Church of England's 43 cathedral school foundations, the majority of which are fee charging, have expressed interest in becoming academies, with nine now in discussion with the Department for Children, Schools and Families.
A report by Halifax Financial Services this week found independent school fees had risen 41 per cent over the past five years, making them too expensive for average-earning scientists, police officers, engineers, journalists and teachers. Sam Freedman, head of research at the Independent Schools Council, said academy status was an attractive option for schools concerned about finances.
"I expect between 10 and 20 independent schools will follow that route," he said. "If a school is confident in its future, there is little point in becoming an academy. I do not see them changing for ideological reasons."
William Hulme's grammar in Manchester and Belvedere in Liverpool will leave the independent sector to become state-funded academies in September. Colston's girls' school in Bristol and Bristol Cathedral school are on a fast track scheme to make the switch a year later. All four are former direct grant schools, which used to offer places to state-funded pupils.