Depends on how much extra you are talking about and what ailine your travelling. If its only about 10kg extra get to check in as early as possible if travelling with kids as most will over look it (by early as possible try to be the first ones to check in) we came back from Oz with about 15kgs over after chrissy and didn't pay a cent for it. the only thing was one of our bags went missing from our connecting flight but turned up the next day. put this down to the connecting flight and being over weight that they just put it on the same flight the next day.