The minimum check-in age for most hotels in the United States in 2026 remains 21 years old, particularly in major tourist hubs like Las Vegas, Miami, and New York City. This is largely driven by liability concerns and the presence of "minibars" or alcohol service on-site. However, many "economy" chains and mid-range hotels like Motel 6, Red Roof Inn, and Hilton Garden Inn often allow guests as young as 18 to check in, provided they have a valid credit card and ID. In Europe and many other international destinations, the standard check-in age is almost universally 18. For 2026 travelers under 21, the "pro-tip" is to always check the specific "Terms & Conditions" or "Policies" section of the hotel's website before booking, as even hotels within the same brand can have different age requirements based on local management and state laws.