Most states allow hotels to exercise discretion in setting their own minimum age requirements, according to USA Today. For many hotels, the minimum age to book a room is 18, the legal age of majority for all states as of 2014. Some hotels have higher age requirements.
As of 2014, the legal drinking age in all states is 21, and many hotels will not rent to anyone under that age to avoid legal liability. Many establishments offer alcohol through room service or in mini-bars, and a hotel may be at risk if an underage person gets access to alcohol on the property. Still other hotels simply prefer an older, more upscale clientele, and may set their minimum age requirement as high as age 25.