Can I book a child as an adult?

[beachbodyunready]

Pricing up holidays for an AI package trip that will include myself, DH, DM and 2dc's.
Children will be 5 and 13 at the time of travel. Pricing it up it appears that if I book eldest DC as an adult the total price drops by around £600! I know it's mad but true, I think it's down to not having an under occupancy in one of the rooms.

So does anyone know if I'm allowed to do this? Or will we come unstuck and prevented from going?

Dont they ask for DOB when you book?

If not then I dont see why it would be an issue. Although I am a scaredy cat and would be too worried my holiday would be void

Depends on who you book with. Some class adults as 12+, others 16 or 17.

I'm a single parent so it makes a difference to me as I need my eldest to be classed as an adult so I can book a second room.

And no, I don't think it will stop you from going. I couldn't book a second room at the Travel Agents, but it was fine online.

It will be fine. However by booking a child as an adult you would incur the air passenger duty charge on her flight . However you can reclaim this for under 16s , via your tour operator if it is a package holiday.