Labor secured 50.12 per cent of the two-party vote against the coalition's 49.88 per cent.
The result represents a swing of 2.58 per cent against the ALP.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
The returning of the writs means all the polls have now been declared for both the House of Representatives and the Senate.
"The election, as it were, is formally concluded," Australian Electoral Commission spokesman Phil Diak said.
However, the commission is still finalising the full distribution of preferences for information purposes.
This occurs in seats where the contest wasn't between the two major parties or the result was determined on primary votes.
"(But) any changes in the two-party preferred statistic would be quite marginal," Mr Diak said.
For example, it changed by just one vote on Friday afternoon as counting continued.
Mr Diak said the definitive result would be "locked off" in around a week's time.
Some 93.21 per cent of eligible voters - or 13.13 million Australians - voted in the 2010 federal election.
Of those, 5.6 per cast an informal ballot for the lower house.
That's an increase of 1.6 percentage points on the 2007 informal vote.
