What age is classed as a child for hotel stays? Holidays by National Express Support 23 April 2019 16:04 Updated In the UK most hotel child policies apply to children aged 15 and under. Please note that when booking with us, you should enter their age at the time of travel, not at the time of booking. Related articles Do you charge for an infant on a booking? What confirmation will I receive after making my hotel break booking? How much do I pay for child hotel accommodation?