A bag-in-box container for storing and transporting liquids with a maximum safety tap for direct consumption or consumption through flexible tubes, wherein the container comprises a flexible bag with a high level of impermeability to liquids and gases for containing a liquid product and a stabilising box in which the bag is housed once it is filled with the liquid product, said bag including a tap comprising: - a hollow main body, with first and second open ends, that can be covered at the end portion thereof; - a tap connector, at the first end of the main body, for coupling to the bag by means of a second connector, welded to the bag; - a third outlet spout, in the main body, to serve the liquid product from the main body; - two windows, at the second end of the main body, which pass through the main body; - an access hole, inside the main body, which is in fluid communication with the third spout, which is configured to be automatically emptied after each dispensing and closure; - an elastic flow interrupter, housed in the main body, and comprising a first portion, fixed by pressure internally to the main body, and another elastic portion able to deform to alternately cover and free the access hole; - an actuator element with two flanges, which can be housed at the second end of the main body, and comprising: an axially rotating bushing able to move in the main body; and a shutter fastened with the elastic element; - said flanges being configured to be actuated to move the bushing away from the closing seat, from a normal closed position to an open position in which the liquid has access to the main body; - grooves, in the main body, in prolongation of the windows, for blocking the flanges, in closed tap position, by means of the axial rotation of the bushing; and lateral displacement of the flanges in said grooves; characterised in that the tap comprises: second grooves in the main body, in prolongation of the windows, for locking the flanges by axial rotation of the bushing and lateral displacement of the flanges in said second grooves in a permanently open position of the tap; a second spout configured as a hollow dip tube, towards the bag, concentric and inside the connector moving away from the main body, until the proximity of a base provided in the connector, which, in a full container position in which the container is welded to the bag and connected by pressure to the connector after filling the bag, includes a wavy free edge, which prevent the blocking of the exit of the content in the bag through the second spout and the third outlet spout until a complete emptying of the container; wherein radial fins are internally configured in the third spout, in the second third of said third outlet spout from its extremity attached to the main body, as retention means for retaining residual liquid by internal wetting, having at the end of the third outlet spout a reduction in diameter at its end, which is turned into a circular inner edge determining retentions means for retaining said cumulative wetting. - a hollow main body, with first and second open ends, that can be covered at the end portion thereof; - a tap connector, at the first end of the main body, for coupling to the bag by means of a second connector, welded to the bag; - a third outlet spout, in the main body, to serve the liquid product from the main body; - two windows, at the second end of the main body, which pass through the main body; - an access hole, inside the main body, which is in fluid communication with the third spout, which is configured to be automatically emptied after each dispensing and closure; - an elastic flow interrupter, housed in the main body, and comprising a first portion, fixed by pressure internally to the main body, and another elastic portion able to deform to alternately cover and free the access hole; - an actuator element with two flanges, which can be housed at the second end of the main body, and comprising: an axially rotating bushing able to move in the main body; and a shutter fastened with the elastic element; - said flanges being configured to be actuated to move the bushing away from the closing seat, from a normal closed position to an open position in which the liquid has access to the main body; - grooves, in the main body, in prolongation of the windows, for blocking the flanges, in closed tap position, by means of the axial rotation of the bushing; and lateral displacement of the flanges in said grooves; second grooves in the main body, in prolongation of the windows, for locking the flanges by axial rotation of the bushing and lateral displacement of the flanges in said second grooves in a permanently open position of the tap; a second spout configured as a hollow dip tube, towards the bag, concentric and inside the connector moving away from the main body, until the proximity of a base provided in the connector, which, in a full container position in which the container is welded to the bag and connected by pressure to the connector after filling the bag, includes a wavy free edge, which prevent the blocking of the exit of the content in the bag through the second spout and the third outlet spout until a complete emptying of the container; wherein radial fins are internally configured in the third spout, in the second third of said third outlet spout from its extremity attached to the main body, as retention means for retaining residual liquid by internal wetting, having at the end of the third outlet spout a reduction in diameter at its end, which is turned into a circular inner edge determining retentions means for retaining said cumulative wetting.