The four group winners in the ongoing 2026-27 UEFA Nations League B earn direct promotion to League A, with the league phase concluding in November after recent September and October international windows. Switzerland leads Group B1 after strong results including a 3-0 win over North Macedonia, while Northern Ireland tops Group B2 ahead of Hungary. Austria sits first in Group B3, and Poland or Bosnia and Herzegovina remain in contention in Group B4 depending on final fixtures. Runners-up will enter promotion play-offs against select League A sides, adding complexity to the transition toward the restructured three-league format starting in 2028-29. Recent form, goal difference, and remaining matches against lower-placed sides will determine the promoted teams.