Linfield and Crusaders will play in next season's Scottish Challenge Cup, after the competition received approval from UEFA for expansion.
The competition is for Scottish league sides outside of the top flight, along with Under 20 outfits from Scottish Premiership teams.
The new format will see the Northern Irish duo along with Welsh sides The New Saints and Bala Town (the top two clubs in Wales), along with four teams from the Scottish Highland League and four from the Scottish Lowland League.
The competition will kick off in October, but the sides from Northern Ireland and Wales will not enter the cup until the last 16 stage in October.
One of the Belfast sides will be guaranteed a home tie, while the draw will be set up so that both Northern Ireland and Welsh sides will not face teams from their own league.
"We are very pleased to be supported by Uefa in delivering an element of cross-border competition through the invitation to our colleagues in Northern Ireland and Wales," said Scottish Professional Football League chief executive Neil Doncaster.
The SPFL say the majority of fixtures will take place during international weekends, while BBC ALBA, S4C and Premier Sports will all show live matches.
Championship winners Rangers lifted the trophy last season, beating Peterhead in the final at Hampden.