Beware of online agencies with 'available' rooms on search engines such as Trivago. Currently taking bookings for Ibis Wembley via a company 'Stayforlong', Ibis Wembley website doesn't have any availability. I've come across this before with spurious outfits linked to Trivago, on that occasion I spoke directly with the hotel (Radisson) concerned and they confirmed it was a problem, and of course illegal and had referred it to the authorities.
There shouldn't be issues with the likes of reputable ones such as Booking.com, Expedia, Hotels.com, etc. or booking direct with the hotel.