Pizza restaurant giant Domino's has been left red-faced after a blanket 15 per cent surcharge short-changed some regional customers on Melbourne Cup Day.
Domino’s Queensland-based headquarters has apologised for the error which saw customers at Domino’s Wendouree and Ballarat stores pay a public holiday surcharge on Tuesday.
Cities and towns outside of Melbourne, including Geelong and Wodonga, celebrate a local show day instead of Melbourne Cup Day.
Domino’s issued a statement apologising for any inconvenience caused to customers.
Affected customers can take proof of purchase to the Domino’s store for a refund of the surcharge.
Unclaimed refunds will be donated to the store’s local State Emergency Service group.
Domino’s was unable to say how many other stores had been affected by the error but confirmed the directive had been issued statewide.
A spokesperson said it was expected unclaimed donations would amount to a few hundred dollars for each store.

Quinton Wilkinson contacted The Courier after his son paid a $5.50 surcharge.
“It was just a case of someone who hadn't done their homework charging trying to make an extra buck,” Mr Wilkinson said.
“It was just the fact they’re charging everyone else, it’s not an onerous task for me, I can afford it ... but we have to look after everyone in the community.”
Moyne Shire, Warrnambool, Gannawarra Shire, Geelong, Macedon Ranges, Colac Otway Shire, Hepburn Shire and Wodonga substitute Melbourne Cup for a local cup day.
A spokesperson said Domino’s staff were paid for a regular day and pay was unaffected by the error.
In Victoria restaurants, cafes and bistros which charge extra for weekends or public holidays must display the surcharge on their menu.
Surcharges are a commercial decision for an individual business to determine which, if any, days a surcharge will apply, and do not fall under Australian Consumer Law.