Ticket-holders for the Best Song Ever stars' stadium gigs are being cautioned to check they are old enough to actually attend when the gigs begin in Sunderland on May 28.
The city's Stadium of Light is urging people to check restrictions before they set out because under-12s will not be allowed to enter if they have a standing ticket.
And anyone under the age of 16 has to be with an adult. Sunderland AFC, which plays at the venue, says the restrictions are in force to ensure fans are safe.
Stewards will be on the gates and will turn back those who fall foul of the age limits. The Where We Are world tour gigs sold out in a matter of minutes and some fans could have failed to pay heed to the terms.
The club says no one under 12 will be allowed into the standing area on the pitch and should contact their booking agent if they have the wrong ones. Under-12s will be only allowed in seated areas, and gig-goers are advised to carry ID with their age, particularly if they look younger than they are.
Any group of seven under-16s must be with at least one adult.
The stadium shows are a step up from the arena dates the band played last year on their Take Me Home tour.
The head of security and safety at Sunderland, Paul Weir, said: "The age restrictions are laid down by the promoter to ensure the safety of everyone attending the show, which is a very different dynamic to anything we have staged at the Stadium of Light previously.
"The GA (general admission) pitch standing area is not a suitable environment for under 12s and anyone who doesn't meet the age requirements will not be allowed to enter the stadium. We would advise fans to check their tickets carefully in advance to avoid any issues on the day."