The UK will ban the installation of new 5G gear from Huawei starting in September 2021.
Britain regards the Chinese firm as a security risk, following the lead of intelligence allies like the United States.
Britain's latest move is part of a plan to purge Huawei's equipment from high-speed mobile networks.
It has already banned telecoms from buying Huawei 5G kit after the end of the year and ordered all Huawei equipment to be removed from its 5G network by the end of 2027.
But Monday's (November 30) announcement came as a surprise for the industry, according to media reports.
Earlier this year, the government was actually encouraging telecoms to stock up on Huawei gear.
Telecoms need spare parts to maintain and update networks, and there were fears that U.S. sanctions on the Chinese company could disrupt supply lines.
With the new ban, some stockpiles may prove useless after the September 2021 deadline.
Britain has also announced a new strategy to diversify the 5G supply chain, including a 250 million pound investment.
So far, no response from Huawei on the new ban.
But the company has said it was "disappointed" at being excluded from Britain's 5G roll-out.