The England cricket team’s kit-maker is accused of failing to pay a key supplier, even as it seeks a £1bn sale.

Castore has been accused of failing to settle a £100,000 invoice due almost a year ago in what industry sources said reflected a long-running pattern of paying suppliers late.

The delays reflect an escalating cash squeeze at the Manchester-based start-up, which has struck high-profile but costly kit deals with some of Britain’s biggest sports teams.

The revelations will raise concerns for bankers attempting to sell the business, which was valued at £950m in a funding round three years ago.

Brothers Tom and Phil Beahon, Castore’s founders, launched the company as a British rival to global sportswear giants Nike and Adidas.

However, the business’s growth has been built on paying high fees to sports teams it partners with, including England Cricket and Everton, in an arrangement now putting pressure on its finances.

This strain has been highlighted by a dispute with SunGod, a premium sunglasses manufacturer that is chasing a £100,000 invoice due 11 months ago.

An industry source said: “They are spending so much on new acquisitions that something has got to give. And it’s always going to be suppliers first.”

Castore’s revenue has soared from £48m to £335m in the last three years, fuelled by deals with sports teams including Rangers FC, Bath Rugby and F1’s Oracle Red Bull racing team.

However, the brand pays for the opportunity to sell official kits and merchandise, and increased expenditure has hit Castore’s profitability on individual sponsorship deals.

This led to the company losing £40m last year alone, up from £25m in 2024.

It highlights mounting financial pressure on the fast-growing start-up, which has billed itself as a premium alternative to larger sportswear rivals.

Founded in 2015, Castore achieved rapid success by striking sponsorship deals with football clubs around the world, including the likes of Aston Villa, Bayer Leverkusen and Newcastle United.

This was largely bankrolled by investment from a string of eclectic high-profile backers, including Mohsin Issa, the Asda co-owner, and Sir Andy Murray, the former tennis champion.

Sir Jim Ratcliffe, the Manchester United co-owner, recently invested tens of millions of pounds as part of a deal to sell his clothing brand Belstaff to Castore.

US investment giant Raine Group is also a key backer, alongside UK venture capital fund Felix Capital.

One City grandee said he turned down the opportunity to invest in Castore because of concerns about its business model.

Revelations of financial volatility strike a remarkably different tone to that portrayed by Tom Beahon, a former professional footballer at Tranmere Rovers.

After tasking bankers at JP Morgan with pursuing a £1bn sale, Mr Beahon said in October that the company had been approached by China’s Anta and Li-Ning, which he called the “Nike and Adidas” of China.

A regulator commentator on LinkedIn, he said on social media last week that “Castore is living proof that entrepreneurial businesses continue to thrive in Britain”.

Financial strain has also coincided with quality issues at Castore.

The company came under fire in 2023 when Aston Villa’s “wet-look” shirts prompted complaints from players who said sweat-soaked jerseys affected performance.

Problems with the quality of shirts and late delivery of training gear and merchandise led to a number of clubs ending partnerships early with Castore, including Villa, Newcastle United and Wolverhampton Wanderers.

Castore declined to comment.