Irish football fans will be turned away from this weekend's World Cup Qualifier if they have Danish tickets.
The Irish allocation for the match in Copenhagen sold out quickly.
But some supporters have tried to buy tickets reserved for the home side.
The Danish FA is warning there will be no refunds for the wrong tickets and fans will be turned away at the gates.
Communications Director Jacob Wadlund says it is nothing personal.
"We love to have Irish fans; we have had them several times, and we love the spectators.
"We have had such a big demand for tickets for the match, but the rules are we give about 5% of the tickets, we gave a bit more than that actually."