Although you should obtain consent from your former partner before any international travel much will depend on where the children’s passports are located. You will require the children’s passport details to book airfares for international travel and for visa purposes.
If you hold the children’s passports you may be able to travel overseas with the children without your former spouse’s permission. However, this is risky as there may be an “Airport Watch List order” in place preventing the children from travelling overseas. If such an order exists you and the children may be escorted off an airplane by Australian Federal Police on the date of your departure.
If your former spouse holds the children’s passports, then you will need to make arrangements directly with them, by providing details of your proposed travel with the children including how the other parent can get in touch with you and/or the children whilst you are overseas. You will also need to make arrangements to obtain their passports prior to your proposed departure date.
It is best that you take the above steps before you book any travel with the children. If you do not obtain the consent of the other parent he or she can make an urgent application to the Family Court or the Federal Circuit Court to place the children’s name on the Airport Watch List and thereby preventing the children from leaving Australia. This application can be heard by the court “ex-parte”, which means that the application can be heard, and orders made, in your absence if the court is satisfied that you pose a flight risk.