Co-hosts England, Republic of Ireland, Scotland and Wales will not automatically be in the 2028 European Championship finals and must go through qualifying, though two spots are reserved if they fail.
The decision was taken by European governing body UEFA's executive committee on Wednesday in Bilbao ahead of the Europa League Final.
Hosts or co-hosts have automatically qualified for the Euros in recent editions, barring the 2020 tournament which had no automatic berth as it was held in 11 host cities across Europe.
The four co-hosts will be drawn into separate groups, with 12 group winners and eight best runners-up advancing directly to the final 24-team tournament.
"Two spots in the final tournament will be reserved for the two best ranked host nations who are not qualified as group winners or best runners-up after the completion of the qualifying group stage," UEFA said in a statement.
The remaining spots will be assigned via playoffs between the remaining runners-up in the qualifying groups and the best ranked 2026-27 UEFA Nations League non-qualified group winners.
If both reserved qualifying slots for co-hosts are used, then eight teams will compete in two paths for two spots, with single-leg semifinals and a final.
If only one reserved qualifying slot is used, then 12 teams will compete in three paths, like the system used for Euro 2024.
If no reserved qualifying slots are used, which means all four co-hosts qualify, then eight teams will play four home and away playoff ties to qualify.
Euro 2028 will be held across nine venues in the United Kingdom and Ireland.
England finished runners-up at Euro 2024 while Scotland were knocked out in the group stage. Wales and Ireland did not qualify for last year's tournament hosted by Germany.
