The appeal was heard by Justices Pamela Andrew, Gus Andree Wiltens and Michael Buss this morning.
Bainimarama is challenging the judgement delivered by High Court Judge Justice Daniel Goundar last year.
Bainimarama had sued the government for miscalculating his pension and gratuity entitlements.
He had argued that the 20 percent salary reduction that was announced on the 27th of March 2020 was temporary and that the calculation should use the original salary of $328,750.
Bainimarama claims that his pension should have been $246,562.50 annually, but was instead reduced to $184,921.87.
He also alleges that the gratuity payment was reduced and should have been $770,507.87, but he was paid $433,296.75.
Bainimarama's lawyer Devanesh Sharma says there was no real analysis by the Judge on the evidence.
Sharma says the determination made in March, 2020 had an expiry which was 31st of December, 2020.
Solicitor General Ropate Green says that to replace the previous determination of temporary reduction another determination should have been made.
