Between September 2015 and February this year, 7-Eleven Stores have back-paid $173.6 million in wages, interest and superannuation to 4043 current and former franchisee workers.

It followed an inquiry which found several 7-Eleven franchisees had been deliberately falsifying records to disguise the underpayment of wages.

The inquiry led to 11 court cases resulting in more than $1.8 million in penalties, including for operating unlawful cash-back schemes, paying unlawful flat rates to workers, and falsifying records.

Fair Work Ombudsman Sandra Parker said on Friday a "compliance partnership" had led to significant improvements for workers.

Action included putting in place a biometric time recording system across all stores, requiring employees to clock in and out with a thumbprint, cross-checked against employee facial recognition images and store rosters.

As well, all staff were required to be paid electronically and an internal investigations unit was set up.

The past two audits of the pay system had found no further under-payments.

"After widespread non-compliance in its franchise network was identified, 7-Eleven has implemented extensive high-tech systems, training and employee assistance programs across its business," Ms Parker said.

She said franchise networks were a priority sector for the FWO and reminded franchisors they can now be held responsible for their franchisees' conduct.

There are more than 700 stores in the 7-Eleven network across NSW, Victoria, Queensland, Western Australia and the ACT.

Australian Associated Press