Abstract: In accordance with the present inventive concept, there is provided a method for sealing a flexible package of collapsible type. The method comprises providing a first seal extending transverse a filling channel of the flexible package and providing a second seal extending transverse a filling channel of the flexible package. Said second seal overlaps said first seal such that a combined seal is provided comprising a top portion formed solely by a first sealing unit, an intermediate portion formed by the first and a second sealing unit, and a bottom portion formed solely by the second sealing unit.