Other Load Planner
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance
Equipment / Tooling; Human Factors
After flight was airborne for two hours; Load Planning was notified of incorrect weight manifested for a [loading document item].  Weights were invalidated to correct known weight error. After the correction was made in the [document]; due to cargo system constraints the commodity's new weight was corrected in their operating system but wasn't able to transfer into [the computer system].  Cargo help desk was reached and requested to forward the airway bill for known pallet weight.  Loading documents were finalized and new weights sent generating a change of 8;340 lbs. representing 1.74% change from the original takeoff weight.
Air carrier Load Planner reporting receiving an 8;340 lbs revision (1.74% of TOGW) after the affected flight had been airborne for two hours.