A packaging system for liquid product is described in which flexible bags (1, 5, 13, 26) made of a suitable plastics devoid of any outlet valve or base for attachment of an outlet valve thereto are employed. An outlet for product is formed by a consumer forcing an elongate outlet member (6, 19, 31) having a spike (7, 22, 32) at its operatively inner end into the bag. The outlet member has an outer diameter which receives the plastic bag material (16, 18, 23) in a deformed and stretched condition in which it closely engages the outer surface of the outlet member. An externally accessible valve (4, 9) for controlling the flow of liquid through the outlet passage is associated with the outlet member. An outlet unit for use in the system is also described.