The Bougainville Referendum Commission, the BRC, says the six week delay in the holding of the vote on independence from Papua New Guinea, will ensure a better roll.
It was announced at the weekend that Bougainville's referendum on independence will now start on 23 November.
It has been moved from 12 October, and earlier, from June.
The BRC had been calling for the extension, saying they needed more time to complete the roll.
Its chair, former Irish Prime Minister, Bertie Ahern, said the extension will give them time to complete two critical tasks that both the public and leaders have demanded.
He said these are, enrolling Bougainvilleans in hard to reach locations, and extending the public display period to three weeks so Bougainvilleans have time to thoroughly check the preliminary roll ahead of the issuing of writs.
Writs are to be issued on 27 September with the preliminary roll to go on public display on 31 August.