Spending the night at Madrid airport is not that traumatic, as several services are available 24 hours a day. While there are hotels nearby, not all passengers are willing to pay for one night when their flight leaves after midnight or early in the morning. While there are Air Rooms inside the airport, which are suites with a common living room to rest for some hours, these are payable. If you are tight on money, you better find another alternative. The most important thing is that the airport is open 24 hours a day.
Where to rest: Terminal 1 is not very comfortable nor does it have many seats, while terminals 2, 3 and 4 have more space and benches, but not very comfortable. Some of these do not have armrests, and those are ideal to rest on two or three of them. If you find two or three together and unoccupied, do not hesitate and grab them. Take into account that none of the terminals has areas with too much privacy and the lights usually stay on, so you best have an eye mask. If you have to sleep on the floor, have a blanket, since it is usually cold. Another option (paying around €30.00) is using one of the VIP rooms. Some of them are even available 24 hours a day: Iberia Velázquez, Neptuno and Cibeles. SEE VIP LOUNGES
Luggage: In terminals 1 and 4 there are luggage storage offices open 24 hours a day, and therefore, if your flight leaves early in the morning, you can leave your bags and sleep without having to watch your belongings, and then get them when is check-in time. The Terminal 4 office is in the Arrivals Lobby and in Terminal 1 it is opposite baggage room 2.
Eating and drinking: There are options open 24 hours a day in terminals 1, 2 and 4. In turn, there are vending machines with drinks, sandwiches and snacks in all terminals.
Restrooms: Showers available only inside the VIP areas and the Air Rooms.
Wi-Fi: The airport has a free and unlimited service, and several access points in different areas of the terminals. There are also charging stations and printers.
Other services available around the clock: ATMs, currency exchange bureaus, gas stations.
On level -1 of Terminal 4 there are suites from Air Rooms (Tel +34 913 276 015). In the proximity of the enclosure you can find numerous alternatives, many of which provide courtesy transport services for their guests. Ibis Madrid Aeropuerto Barajas (Tel +34 913 010 999), TRYP Madrid Alameda Aeropuerto Hotel (Tel +34 917 474 800), Meliá Barajas (Tel +34 917 477 700), Clement Barajas Hotel (Tel +34 917 460 330), Täch Hotel Madrid Airport (Tel +34 913 010 721), Hotel Villa de Barajas (Tel +34 913 292 818), Hostal Avenida Barajas (Tel +34 913 056 929), Hospedaje Los Rosales (Tel +34 913 291 681), Hostal El Príncipe (Tel +34 917 477 965).