B747-400
Flight Crew Air Transport Pilot (ATP)
Training / Qualification
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance
Flight Crew Returned To Departure Airport
Human Factors
We departed for our flight and was notified several hours later via SAT [phone] that [air carrier] had discovered a mistake in the manner in which it calculated our cargo weight. They discovered that their operator incorrectly measured several pallets resulting in a lower than actual weight. After being notified by our company; it was decided to return to [origin]; our departure airport. We requested and company provided new burns and a much higher zero fuel weight (approximately 45;000 lbs). After reading the 'Overweight Policy' in the QRH; and taking other factors into account; we decided to dump our fuel to 60;000lbs remaining. This would give us a landing weight of 625;000; well below our max landing weight.Landing and taxiing were uneventful.It is very difficult to state what as a crew we would have done differently to prevent this situation. We rely on many different people to do their jobs correctly to ensure we have a safe flight. There is very little we could have done in this situation short of standing next to the scale operator to ensure he/she was preparing weight tags properly.
B747-400 First Officer reported they departed with incorrect cargo weight information; resulting in a much heavier gross weight than planned for. They returned to departure airport.