There used be be a law saying under 17's cannot enter into a contract, but best to check with the hotel direct as it may be different abroad.

Good luck

If you were to book the room for them the contract would presumably be in your name so I don't see that it would be a problem.

if you try to book a room on the likes of travel republic the site asks you for their ages and two 17yr olds are not able to complete booking without a adult being added
regards tracey

I'm not sure about the contract thing Glynis as I know Olympic holidays used to take booking from those between 16 and 18. Know a couple of 17 year olds who have been on holiday with them (without parents ).

I'm not sure if that is going to help the OP though as olympic seem to just book package holidays, I don't think they do accommodation only.

I wonder if any Greek apartments would take a direct booking from the UK that might be a way round it, I would think they would be glad of the business and wouldn't be so bound up in red tape as the UK travel industry.

Does hotels.com or booking.com ask for ages ?

On one of those sites I have booked a hotel and not paid until checkout, all you need is a credit card to secure the booking - maybe that would be a way round it ?

In the UK you can't enter into a legal contract if you're under 18. I know you book under 18s with Thomas Cook but it can't be done online. It has to be done in store, with the parent to sign the contract. They also have forms they can send out for flight only bookings. Olympic have a downloadable under age waiver form.
Perhaps other companies have something similar if you call them?