Hundreds of people look set to miss out on the trip of a lifetime, to next year's centenary Anzac commemorations at Gallipoli.

But it means a second chance for others.

300 people whose names came out of the Gallipoli 2015 ballot haven't yet accepted their double passes, or completed travel details online.

They have until midnight tonight to do so, before their passes are reallocated to people on a waiting list.