To think an 18 year old can have a cider with a meal?

[boowaitingforbaby]

Ok, so my 18 year old cousin didn't have her ID but I've always been of the thinking that 16 & 17 year olds can have a pint of cider with a meal.
Got her a cider, about 3/4 in, bar staff come up, don't speak to me, but take the drink off her telling her she can't have it.
(Again, no word to me, the person who purchased the drink)
I complained to the supervisor, saying the law states that a 16 & 17 year old can have one drink so even if she is under age (she isn't) it shouldn't have been taken off her.
He said that it needed to be a low alcohol cider for that, but after some furious googling, I cant find anything about that.
(Obviously I didn't shout or get too angry, I more focused on the rudeness that no one asked me, the person who bought the drink)
Am I being unreasonable??

Not meaning to cause arguments or anything with this post. I'm less bothered about the actual "no id no drink" ethos - I understand that completely. Cousin was silly for not bringing ID. Lesson learnt.
I was more bothered with rudeness and then the making up of licensing laws. I understand bars and pubs can refuse anyone service and have their own rules within the bar - the supervisor did not say that this was a rule within the bar. He said the law that said that you can be 16 or 17 and have a wine, beer or cider with a meal stated that it must be low alcohol. I have now found out this is not true.
If the bar is under its own rule of no under 18s served under any circumstance I appreciate and understand this. But the bar in question did not say that this was the case.

boowaitingforbaby I think that you have been incredibly patient with people citing irrelevant things to you.

I used to manage a pub that was part of a chain and our company policy was 0 tolerance to any alcohol being given or bought for under aged people, even with a meal. A pub is entitled to make that decision even if it is legal. However I agree that you should have been spoken to as the adult, and explained that the pub did not allow this.

@Stoprightnowplease thank you 🙂

@hannahintheworks thank you! I understand every pub has their right to refuse service to who ever they want, just peeved it wasn't said to me and snatched away like I'd tried to do it underhand when i thought i wasn't doing anything wrong!
Never mind!