Chief election commissioner Pat Bradley, said the ballot had been meticulously prepared to combat fraud and needless confusion among the voters.
Polling stations will be open all day and ballot boxes will then be transferred to Belfast's King's Hall, where the counting will start on Saturday morning with the aim of announcing a decision by early afternoon. To be eligible, voters must have fulfilled a three-month residency period in the province.
However, the system has been deliberately devised to prevent identification of voting patterns between Catholics and Protestants, and Nationalist and Unionist areas. Smaller boxes from different regions will be put together to prevent tracing.
There have been complaints that many voters have not received voting papers despite requests, and a number of parties say they intend to complain to the electoral commission.