**The 2026–27 UEFA Nations League B league phase begins September 24, 2026, with four groups of four teams each playing a home-and-away round-robin through mid-November.** Group winners earn direct promotion to the 2028–29 Nations League A, while second-placed sides enter promotion play-offs against League A third-placed teams in March 2027; third-placed teams face relegation play-offs against League C runners-up. Recent team movements from the 2024–25 cycle shape the field: incoming sides include Bosnia and Herzegovina, Hungary, Israel, Poland, Scotland, and Switzerland (relegated from League A) plus Kosovo, North Macedonia, Northern Ireland, Romania, and Sweden (promoted from League C). Seeding drew on 2024–25 final rankings, placing stronger sides such as Scotland, Switzerland, Hungary, Austria, Poland, and Israel as early frontrunners in their respective groups. No matches have been played yet, so current trader positioning reflects squad depth, recent international form, home/away records in prior cycles, and fixture difficulty. The tight schedule and potential for upsets in shorter groups keep several promotion paths competitive until the autumn results clarify momentum.