Heartbroken pupils and parents were left in tears as they were told their 700-year-old school will close for good.
The devastating news about Ruthin School in Denbighshire was delivered the day before children broke up for summer.
A number of independent school – sometimes called private schools – have been struggling, with St Gerard’s in Gwynedd also closing and owners of both citing financial pressures.
A spokesperson for Ruthin School, one of Wales’ oldest, said it had “not been possible to establish a financially viable way forward”, and it would enter administration.
The body representing independent schools believes new VAT rules for fees have added to a “perfect storm” for the sector.
Last week, Llandovery College in Carmarthenshire said it faced a £1m deficit after pupil numbers fell, and also cited the impact of the 20% VAT rate on private school fees.
Ruthin pupil Hari, 15, said he was “absolutely devastated”, describing how the small classes make it “really easy to learn”.
He was one of around 240 pupils and had been looking forward to returning in September for his final year and to sit his GCSEs.
But he will now need to find a new school.
“I don’t know what we’re going to do,” his mother Arwen said, struggling to hold back tears.
“My children come on a scholarship because we couldn’t afford the fees – we’re a working class family.”
She has another child who was due to start at Ruthin School in September.
But all parents and staff were informed the school would not be reopening for the new term by email on the afternoon before the final day of lessons.