A sign erected in a Bermagui coffee shop just before Australia Day has created outrage on the internet.

Bega District News reports a blackboard sign was put up in the Mister Jones Open Studio and Espresso Bar in Bermagui, on NSW's south coast, on January 25 and it read: "Yes, we're open on national dickhead day" – a reference to the venue being open for business on Australia Day.

A photograph of this sign has since been shared widely on social media.

On the night of January 25 it was posted on the Meanwhile in Australia Facebook page, which is "liked" by about 700,000 people. By mid-afternoon on Australia Day, it had more than 3000 shares, almost 6700 likes and 1770 comments with many deriding the sign.