The only two independent candidates submitted signatures in support of their bids with the Central Election Commission (CEC) on Wednesday.
Former prime minister and opposition leader Mikhail Kasyanov provided 2.067 million signatures, just above the 2 million required for independent candidates. Candidates nominated by parliamentary factions were exempt from the requirement.
Kasyanov, the sole liberal opposition candidate after SPS nominee Boris Nemtsov stepped down in December to make way for the ex-premier, said he was positive he would pass the registration procedures.
"We have done everything required by law, and I cannot imagine any reasons for denying me registration," Kasyanov said on leaving the Central Election Commission.
Reports earlier on Wednesday said an investigation had been opened against the head of Kasyanov's campaign headquarters in Yoshkar Ola on the Volga River, who is suspected of forging several thousand signatures to back the politician's application to run for president.
The other independent candidate who filed his documents today was Democratic Party leader Andrei Bogdanov. Nine other candidates nominated by action groups have failed to pass preliminary registration procedures.
Election authorities have also barred former Soviet dissident Vladimir Bukovsky, who has been living in the U.K. for the past 31 years, from the polls, citing a law that presidential candidates must have lived at least 10 years in Russia.
Other contestants are Communist Party leader Gennady Zyuganov and ultra-nationalist LDPR leader Vladimir Zhirinovsky, who will be running run for the third and fourth times, respectively. They both missed the 2004 elections.
Incumbent President Vladimir Putin's choice of successor, First Deputy Prime Minister Dmitry Medvedev, nominated by the ruling United Russia party, provided his documents on Tuesday.
Medvedev is seen as the clear frontrunner. According to opinion polls conducted in late December, 79% of respondents said they would back Putin's choice for the presidency.
The Central Election Commission is to make a decision on candidates' bids within 10 days from the date their applications were filed.
