Qantas has agreed to pay back more than $7 million in wages and entitlements to head office, corporate and administrative staff who were underpaid for eight years.

Key points: The airline underpaid some head office staff between June 2011 and June 2019

The airline underpaid some head office staff between June 2011 and June 2019 The workers were paid under individual contracts instead of under an award

The workers were paid under individual contracts instead of under an award The backpay will be in addition to a $1,000 "contrition" payment per worker

The announcement was made today by the Fair Work Ombudsman (FWO) which investigated the underpayments after Qantas self-reported the lapse.

The FWO said Qantas had already paid out $7.1 million to 638 employees who were underpaid between June 2011 and June 2019.

It is the latest in a long line of underpayment cases involving large and small employers including the likes of Woolworths, Commonwealth Bank, Rockpool Dining Group and the ABC.

The FWO said Qantas had entered into a legally binding undertaking to make the back payments which were a result of incorrectly paying some marketing and administrative staff under individual contracts instead of under the relevant enterprise agreements.

That resulted in employees getting short-changed on wages, overtime, annual leave entitlements and superannuation.

The airline has agreed that all backpay will be calculated using above market interest rates, in addition to a $1,000 "contrition" payment per worker.

Fair Work Ombudsman Sandra Parker said "three further pay audits will also be conducted by an independent auditor, which will benefit Qantas' current and future employees".

In addition to the underpayment, Qantas said it also overpaid some workers a total of $22 million.

The airline said it would not recover overpaid monies and that only 17 per cent of the 1,000 past and present staff affected had been underpaid on a net basis.

"We sincerely apologise to all our employees caught up in this misclassification issue, especially to those who were underpaid as a result," Qantas group executive Rob Marcolina said in a statement.

We take our obligations as an employer very seriously and have worked with the Australian Services Union and Fair Work Ombudsman to fix this."