The scheme, which is being piloted at six stores across the country, prompts passers by to enable Bluetooth on their mobile phones to receive T-Mobile offers and deals.
Proximity marketing specialist Hypertag has installed Bluetooth tags in the six T-Mobile stores, which send out invites to pick up a free gift and promotional offers to customers' Bluetooth-enabled phones as they pass the store.
Graphics in the shop windows also prompt customers to turn on their Bluetooth to receive the offers.
Once in-store, customers will receive additional information on what their gift actually is or further details on the promotions via Bluetooth.
During the trial, which lasts for one month, T-Mobile will monitor customers' responses to the individual promotions trialling different messages.
Based on the results from the pilot, the scheme could be extended to other T-Mobile stores nationwide.
Elaine Haines, commercial director at Hypertag, said: "Proximity marketing is a really great way for T-Mobile to engage with their customers, providing offers suited to their interests.
"It allows brands to stand out and catch the consumer's eye at the right place and time, and measure the results."
Andrew Coull, director of retail at T-Mobile, said: "We see proximity marketing as an innovative and more targeted way of interacting with our customers, and we hope that they will also see the benefits, as we share with them the information and unique offers which they will be interested in."