In a poll of 1,000 UK people with an interest in the tournament, marketing tech firm RadiumOne found that six of the top ten most associated brands were not sponsors.
The list is topped by sponsors Coca-Cola, which 12% of those polled linked to the competition, and Adidas, on 10% - but Nike is only just behind on 9%, despite having no commercial connection.
MasterCard, Heineken, Visa, Barclays and Budweiser also appeared in the top ten, despite not sponsoring the European Championship.
The results suggest that consumer awareness of brand sponsorship may not extend much beyond a link with football in general – most of the brands mentioned above is the sponsor of a different major competition.
Budweiser and Visa sponsor the FIFA World Cup; Heineken and Mastercard the UEFA Champions League; and Barclays the Premier League. Nike sponsors a large number of national teams, clubs and players.
The other two official sponsors making the top ten cited brands were Carlsberg and McDonald’s. Another three – tyre maker Continental, Turkish Airlines and Azerbaijan's national oil company SOCAR - did not even appear in the 24 names spontaneously offered.
Even after being shown a list of the 10 sponsors, only three – Adidas, Coca-Cola and Carlsberg – were associated with the tournament by more than half of respondents. The average level across the ten sponsors was just 36%.
"With only three weeks left until the tournament starts, sponsors still have much work to do to activate their investment in terms of consumer association," Rupert Staines, RadiumOne’s European managing director, said. "Particularly as non-sponsors are achieving a significant ‘halo’ effect from other football-related sponsorships.
"Sponsors will certainly need to tap into the huge levels of second-screening during the tournament to reinforce their association, such as serving online ads during live matches or highlights shows," he added.