Supporters' loyalty will be rewarded with those who regularly attended games during the Euro qualifying campaign to be given priority.
The decision follows discussions this week between the Irish FA and Uefa.
Priority will be given to block bookers who renewed tickets after the 2014 World Cup campaign and those who bought tickets for Euro 2016 qualifiers.
The success of applications from fans who apply for two tickets will be affected by the "purchasing behaviour" of the second named applicant, according to the IFA.
"Supporters who apply for one ticket will have a level of priority based on their own purchases, while fans who apply for two tickets will have a shared priority allocation," stated the IFA's head of communications, Neil Brittain.
"If a block booker who applies with another block booker, then both remain at the level of priority that they would have had if they had been applying as individuals.
"However, if a block booker applies with a supporter who hasn't attended any Northern Ireland games in recent years, then the priority points will be divided between both."
The move to allow fans to apply for two tickets is good news for Under-18s, who would not have been able to purchase tickets under Uefa rules.
The IFA has over 500 junior campaign card holders who are now eligible to apply for tickets.

The children were taken in a cross-border raid in the Gambella region last Friday, in which 208 people died.
The government has said members of the Murle community were responsible.
Flags have been flying at half mast in Ethiopia as the country mourns those who were killed.
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A government official in Gambella said that the abducted children would soon be rescued, the government-affiliated Fana Broadcasting Corporate reports.
South Sudan acting Foreign Minister Peter Bashir Gbandi is set to travel to Ethiopia's capital, Addis Ababa, on Friday to coordinate the mission, the AP news agency reports.
It says that South Sudan does not want Ethiopian troops to go deeper into the country.
The area where the children are being held "is full of jungle", AP quotes Mr Bashir as saying.
Ethiopia shares a long border with South Sudan and cross-border raids are not uncommon.
Hours after news of Friday's attack emerged, Prime Minister Hailemariam Desalegn said the government had requested permission from South Sudan to enter its territory to pursue the attackers.
The South Sudanese ambassador to Ethiopia also said his country was "cooperating and helping" the Ethiopian army to track down the raiders and rescue the abducted children.
Ethiopia's request to enter South Sudanese territory seems to have been approved quickly.
Before South Sudan's civil war began in 2013, joint security operations between the two countries were common as communities on both sides of the border were often involved in cattle raids.
Residents of Gambella town held a demonstration on Thursday demanding "justice for what happened" and calling for better security.
A mother whose husband was killed and three of her children abducted by the attackers earlier told the BBC that she had no hope of seeing her children again.
"I don't know if they were killed during the crossfire," Chol Malual said. "The fighting was intense and if they survived, they will be probably be killed by the Murles."
The targets of the raid were members of the Nuer ethnic group who live in both South Sudan and Ethiopia, the AFP news agency reports.

The 31-year-old is currently playing in the Indian Premier League for Royal Challengers Bangalore, alongside Sussex and England pace bowler Chris Jordan.
Wiese has made 20 T20 appearances for South Africa, including two against England earlier this year.
He will be available to play for Sussex against Somerset on Wednesday, 1 June and Surrey two days later.
Northern Ireland fans will be allowed to apply for two tickets to the Euro 2016 finals in France.
[NEXT_CONCEPT]
Ethiopia's army has surrounded the area in neighbouring South Sudan where it believes more than 100 abducted Ethiopian children are being held, local media report.
[NEXT_CONCEPT]
Sussex have signed South Africa all-rounder David Wiese for their first two home T20 Blast matches.