The Chinese company’s Mate 20 X 5G device previously has been left out of the launches of other networks – including EE, Vodafone and O2 – over wider concerns around the firm and its security.
Questions have been raised over Huawei’s place in 5G infrastructure, amid fears its equipment could be used to spy on people in the West – an allegation the firm has long denied.
On Monday, the Government delayed a final decision on whether the firm would be restricted or banned, saying it had no choice because it is still assessing the impact of US sanctions against the firm.
Huawei equipment is currently still being used in non-essential parts of some operators’ 5G networks.
Three, which said it will start its 5G network rollout later this year, announced it would start selling the Mate 20 X 5G on Friday to allow customers to prepare for the launch of the new network.
The operator also announced all new and existing customers would be able to access 5G for no extra cost across all its contract and pay-as-you-go plans.
Three did not comment on Huawei’s inclusion, but chief executive Dave Dyson said: “Three is leading the way with 5G, by providing our customers with unlimited data and the fastest speeds. Our customers will be able to enjoy and explore a full 5G experience, at the same cost as 4G.
“The forthcoming months are going to be game-changing and with our unrestricted plans, we are looking forward to unleashing the full potential of 5G to all.”
Sky Mobile, which confirmed on Friday it will begin rolling out 5G in November in six towns and cities, will offer the Mate 20 X 5G alongside Samsung’s Galaxy S10 5G device.
The network’s commercial director, Sophia Ahmad, said: “We will be the only mobile operator to be able to combine the launch of next-generation superfast 5G connectivity with Sky Mobile’s unique features including Roll, Swap and Watch.”
Last month Huawei’s UK boss, Anson Zhang, said “nothing had changed” around the company’s devices despite the US sanctions and scrutiny in the UK.
Mr Zhang acknowledged there has been “confusion” and “uncertainty” around the company’s phones after Google placed software restrictions on the company – which have since been eased – but insisted users “do not need to worry” about using its phones going forward.