Up to 17,000 fans will be allowed at Hampden for Scotland's Euro 2020 matches, but four cities could be stripped of hosting duties.
The European Championship was due to be held last summer in cities across Europe but was postponed due to the coronavirus pandemic.
Glasgow will host three group games as well as one knockout tie after the Scottish Government offered assurances that fans will be allowed to attend.
And UEFA has now confirmed that plans will allow up to 33 per cent capacity at Hampden, just over 17,000 Tartan Army foot soldiers.
St Petersburg is hoping to have 50 per cent capacity while Budapest is set to host games will full stadiums, subject to certain restrictions.
Meanwhile Wembley Stadium, where Scotland will face England in the group, will allow at least 25 per cent attendance.
Munich, Rome, Bilbao and Dublin have been unable to give firm guarantees and have until April 19 to provide information to UEFA or risk the games being moved.
Rome's Stadio Olimpico is due to host the opening ceremony on June 11.
International travel is set to be halted except for Baku, St Petersburg and Budapest.
Fans with tickets can apply for refunds until April 22.
For supporters who hold on to their tickets "a fair ballot will be held to determine which tickets need to be cancelled".
