Ian Paisley will learn in the early hours of Thursday morning whether he will have to fight a by-election to retain his Westminster seat.
Polls in the recall petition close at 5pm tomorrow. The boxes from the three centres in Ballymena, Ballymoney and Ballycastle will then be taken to the Electoral Office's Belfast headquarters.
Counting will begin at midnight. Chief Electoral officer Virginia McVea told the Belfast Telegraph she expected the result to be announced at around 2am.
It is understood that after the votes are counted at the premises near Writer's Square, the result will first be recorded with the office of the Speaker of the House of Commons, John Bercow. Then turnout and the result will be posted on the Electoral Office's website.
It is the first ever recall petition in British parliamentary history and allows voters to have their say on their MP.
Mr Paisley has received a 30-day suspension from the House of Commons for failing to declare two luxury holidays paid for by the Sri Lankan government. He is also currently suspended by the DUP pending an investigation by party officers.
If 7,543 people in North Antrim sign the petition - 10% of the electorate - then a by-election will be held. Mr Paisley has vowed to stand in any future poll.
The petition of recall will be open until tomorrow evening at the Seven Towers Leisure Centre in Ballymena, the Joey Dunlop Leisure Centre in Ballymoney, and Sheskburn House Recreation Centre in Ballycastle.
Sinn Fein and the SDLP registered as formal campaign groups in an attempt to oust the MP.
The Ulster Unionists didn't register but party leader Robin Swann has said he would encourage anyone who believes that what Mr Paisley did was wrong to sign the petition.
In March 2014, Mr Paisley lobbied the then Prime Minister David Cameron against a proposed United Nations resolution to investigate alleged human rights abuses during Sri Lanka's civil war, without disclosing family holidays paid for by its government.
He apologised in July for what he said was his "unintentional failure" to register the hospitality. The DUP's 10 MPs are propping up Theresa May's minority government and Mr Paisley's suspension means he could miss key Brexit votes.
The Recall of MPs Act 2015 limits media reporting during the campaign.
Legislation allows for up to 10 centres to be used and the Electoral Office has been criticised for opening just three, but it has defended the arrangements. Mr Paisley has been North Antrim MP since 2010. The seat was first won by his father in 1970.