3. Bytes

Revenue: £1.82bn

Despite teasing a bumper 2025 with GII tipped to breach the £2bn mark, Bytes Technology Services enters this year’s ranking on the strength of its audited FY24 numbers—still a belter by anyone’s standards with £1.8bn.

Its unaudited 2025 looks to be on a similarly steep upward trajectory.

The Microsoft-focused reseller posted a 13.7 per cent rise in gross invoiced income to £1.23bn in the six months to 31 August 2024, with operating profit jumping 16.3 per cent to £35.6m. While revenue dipped slightly (down 2.9 per cent to £105.5m) due to hardware headwinds, CEO Sam Mudd remained bullish, attributing the pause to customer caution following the UK’s change in government and the looming shift to AI PCs.

“We’ve seen a slowdown in hardware sales,” Mudd told CRN back in October. “People do need to refresh their infrastructure, and at some point, they’ll have to replace their desktops. It’s just a matter of when.”

But hardware isn’t where Bytes hangs its hat. The business has continued to double down on software, cloud, and especially security—with Mudd highlighting deepening ties with the likes of Palo Alto, Sophos, HP, Nutanix and more. Microsoft remains a jewel in its crown, with 130,000 licenses now sold across its client base, generating £39m in annualised GII. That includes plenty of Copilot builds—though Mudd is quick to note the AI assistant is more Trojan horse than cash cow.

“The real value for us isn’t just in selling the licenses,” she says. “It’s about engaging with customers to show how AI can deliver efficiencies in their business.”

Beyond vendor relations, Bytes has invested heavily in its people. FY24 saw headcount rise to 1,130 and new offices open in Sunderland and Portsmouth, alongside refurbishments to its Leatherhead HQ.

With eyes on new logos, stronger vendor ties, and staff development, Mudd says the mission is simple: “Look after our people, serve customers brilliantly, and keep evolving with the market.”