The BYNL is an Under 17 competition that follows the format of the Men's National League. It includes regional phases (Northern, Central, and Southern Leagues) leading up to the national finals series in November.

Starting in mid-September and running until November, the BYNL extends the development environment for New Zealand's top youth players after the winter season. This competition is designed to provide these players with the opportunity to further their development in a more performance-oriented setting.