Ally McCoist, the manager, will be unable to sign any player older than 18 during this summer and next January's transfer windows in a devastating ruling for the Ibrox club.
Rangers had appealed against the ban, imposed by an SFA judicial panel which had ruled that the club and owner Craig Whyte had brought the game into disrepute.
The ban will have major repercussions for the proposed takeover of the club by Charles Green's consortium. If the takeover goes through, the consortium will not have to fund any new signings until next summer, but there will be intense pressure on them to keep existing senior players.
McCoist had previously said there was a risk of the club being relegated from the SPL next season if senior players left and there was a ban.
Rangers' case was presented by Richard Keen QC, but was swiftly rejected by the Appellate Tribunal, comprising Lord Carloway, Spartans chairman Craig Graham and former Partick Thistle chairman Allan Cowan.
The SFA statement said it was "competent" for the initial disciplinary tribunal to impose a ban on signing over 18s for the next 12 months.
The statement went on: "The Disciplinary Tribunal was correct to determine that the conduct involved – especially the deliberate non-payment of very large sums, estimated in excess of £13m of tax in the form of PAYE, NIC and VAT – was attributable to the club as a member of the Scottish FA.
"The Disciplinary Tribunal was correct also in holding that the maximum fine available for this breach was £100,000, and on its own was inadequate as a punishment for this misconduct. It was therefore correct to select an additional sanction."
Rangers could have been expelled from the SFA but that had been considered too severe a punishment. "The Appellate Tribunal observes that serious consideration was given by the disciplinary tribunal to imposing one of these sanctions, which would have had obvious consequences for the survival of the club. The Disciplinary Tribunal rejected these as too severe and this Appellate Tribunal agrees with that conclusion.
"Although the Appellate Tribunal has listened carefully to the representations from Rangers FC about the practical effects of the additional sanction, it has concluded that this sanction was proportionate to the breach, dissuasive to others and effective in the context of serious misconduct, bringing the game into disrepute.
"In particular, the appellate tribunal recognises that the Disciplinary Tribunal decision does not affect Rangers' ability to extend the contracts of existing professional players, including those whose contracts will expire at the end of this season and including also those currently on loan to other clubs."
Response from Rangers:
Paul Clark, joint administrator, said: "The decision to uphold the sanction is not competent in the view of the club and its legal advisers. Such a sanction was not available to the tribunal and should not have been imposed and it is the intention of the club to challenge the determination. Everyone at Rangers is bitterly disappointed and dismayed at this outcome."
Charles Green: "Our group went into the purchase of the club with this sanction in place but we hoped the decision would at least be commuted. We fully support the club as it considers an appeal."