The UK's dominant fixed line telco is hooking up with US-based Navini Networks to carry out the pilots, which will run until March 2006.
BT is looking to test the commercial viability and customer experience of wireless broadband.
A spokesman for BT said the tie-up with Navini was "not a strategic partnership [but] one of many vendors we're testing WiMAX products with".
BT is very much behind WiMAX, with chairman Sir Christopher Bland claiming that it would "take the place of current 3G mobile phones". A service could be in place as soon as the end of next year.