Will the hotel know if you call someone outside with the hotel's landline?

yes. The landline in the hotel room normally only provides calls between the landline in the hotel, and the hotel management system will record the call records of the landline. Therefore, if you use the landline of the hotel to call people outside, the hotel will know. A landline refers to a telephone that is fixed in a certain position and does not move. It is different from a mobile phone (mobile phone) and is mostly used in enterprises.