The deal builds on the existing Wi-Fi hotspots provided by O2 in its mobile broadband deals, and will provide an additional 3,000 access locations, including most branches of Starbucks.
O2 has also announced an upgrade to its Mobile Broadband Connection Manager software, which introduces new features to help users better monitor and manage their data consumption.
This is performed through the addition of a data counter and an automatic notification feature, which alerts users when 75 per cent, 90 per cent and all of their data allowance has been used.
"We appreciate that our customers want to get the most from their mobile broadband service, and we continually look to provide value-added services," said Jonathan Earle, head of Pay Monthly at O2.
"We are introducing two key changes. Firstly, expanding our Unlimited Wi-Fi proposition by introducing BT Openzone Wi-Fi hotspots allowing our customers to stay connected to the people and things that matter to them most.
"Secondly, we know that customers want to be able to track how much data they have used. Our simple data counter gives the control that our customers want."
The software upgrade is available to all existing O2 mobile broadband customers on Windows platforms. Users will be prompted to upgrade the next time they connect using Wi-Fi, or can manually update by visiting the O2 Mobile Broadband Update site.
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