Challenge 25, always
A policy with exceptions is not one.
Because Challenge 25 means twenty-five, and a policy with exceptions is not a policy.
Challenge 25 works precisely because it over-asks. Setting the threshold at 25 rather than 18 means staff are not trying to judge whether someone is a year either side of the limit, and it catches the cases where a mistake would cost the shop its licence and a young person a drink they should not have.
The hard part is not the stranger, it is the regular. Refusing someone who comes in every day, or someone plainly in their thirties who has no ID, feels unreasonable in the moment and is exactly where a policy either holds or quietly stops existing. Logging refusals makes that visible rather than discretionary.
Allergens deserve the same seriousness. Prepacked food made on the premises has to carry a full ingredient list with allergens emphasised, a requirement that exists because a teenager died from a sandwich whose label said nothing. A small shop cannot promise a kitchen free of any allergen, which is why asking at the counter still matters.
A policy with exceptions is not one.
It is an offence for the adult buying.
Natasha's Law exists for a reason.
Ask at the counter and we will tell you if we can get it.