The Arizona secretary of state's office says Jon Huntsman has failed to qualify for the state's presidential primary.
A spokesman for Secretary of State Ken Bennett says the former Utah governor filed paperwork a few hours before Monday's 5 p.m. deadline, but that it was missing a notarized signature from the candidate.
Huntsman spokesman Tim Miller says the campaign submitted what was required and will aggressively challenge the ruling to get on the ballot.
Arizona's presidential preference primary is scheduled for Feb. 28.
It's a Republican-dominated affair because President Barack Obama faces no opposition for the Democratic nomination.
Major GOP candidates Rick Santorum, Newt Gingrich, Mitt Romney, Rick Perry and Ron Paul made the ballot, as did 24 other people.