The Iranian election officials started registering the hopefuls at 8:00 a.m. local time at the headquarters of the Interior Ministry in Tehran.
The presidential hopefuls will have until Saturday to turn up at the venue and hand in their credentials.
The registration is the first phase of an electoral process that will climax on the Election Day and end after all ballots have been counted
According to the timeline of the presidential elections, the whole process will take under 40 days.
On May 26-27, the approved candidates will be announced.
Then the campaigning will begin from May 28 to June 16.
No candidate will be allowed to do any campaigning on June 17, one day before the polls are opened for a single day.
According to the election headquarters, there are 59,310,307 eligible voters across the country, 1,392,148 of whom are first-time voters.
Tehran has the highest number of eligible voters (9.8 million).
There were 64,000 polling stations during last elections, but that number has increased by 10% this year.