Okay, so if the lid is on, it is very secure and will not drip – HOWEVER THE LID HAS the small cut out so it’s always open but it’s very tiny, about 1/4 inch – if you tip the cup upside down it will drop out. If the cup tips over but the sippy cut out is at the top, it won’t spill. Very strong cup, can be used more than once (coffee refills, etc.)