To think this makes no sense - holiday/hotel related.

[NickiFury]

Booking a hotel room - two adults - in the T&C a child under aged 12 goes free (sometimes even under age 18), this seems standard for most hotels

Book the same hotel room as ONE adult with two children, one under 12 and you get charged much more and no child seems to go free.

Can anyone explain this please? So basically I will book the hotel for two adults and then arrive with my older child as the other adult and my younger child who will go free and nothing has ever been said. I just want to understand it though

I don't understand it!

But, will they not realise from the dates of birth on your booking application that you are not two adults and one child?

It has never been a problem. I have always arrived at the hotel with booking reference - usually go through third party - and nothing has ever been said. I queried it once and she said "oh your youngest child goes free" and that was that.

Is there something in the T&Cs that give the free child place with two paying adults?

I know what you mean about feeling ripped off, I was in the same position.

We get cheaper prices for AI holidays now they are over 18, than I did when they were young teens.

Yes make the booking as 2 adults and 1 child. It makes no difference to the travel company, flight company or hotel company. Travel companies charge per two adults. Anything under adult will incur under occupancy charges but if you book for two adults and a child the price will be honoured. I have done this loads of times. if you really need to be sure book via a local travel company.