Straying slightly from your regular "accepted" and "declined", some New Zealand EFTPOS machines have been delivering an odd message.

Payment terminals started showing the internet meme phrase "Herp-Derp Eftpos" after a developer's test update was accidentally distributed, reported tech news website iTnews.

EFTPOS terminals in New Zealand have been spouting the geeky phrase Herp Derp.

Usually, the terminals display the name of the merchant or payments provider on the home screen.

iTnews said the machines had displayed their new messages for several weeks, but New Zealand retailers were not concerned.