The "Expression of Interest" comes on deadline day, with The Times in London reporting earlier this week that the UK and Ireland bid was set to be unopposed.
A joint statement from the five associations read: "We believe Euro 2028 would be one of the greatest sporting events ever held in the UK and Ireland.
"This unprecedented partnership of five associations offers something special to European football, including the potential for an expanded tournament, and we are passionate about maximising the sustainability and legacy benefits for communities across the UK and Ireland."
There had been reported interest from Russia -- before the country's invasion of Ukraine -- and Turkey but so far no other national association has confirmed an intention to bid.
The UK and Ireland abandoned plans to bid for the 2030 World Cup last month in favour of going for Euro 2028.
UEFA, which could expand the tournament to 32 teams, is expected to make a formal decision on April 7.
