New coins ring out Aussie stand-ins

Foreign coins which have crept into common usage in New Zealand are about to become illegal tender.

Massey University banking expert David Tripe says the coins - mostly Australian equivalents of our own 5c, 10c and 20c pieces - will become redundant once the Reserve Bank issues its new coins and scraps the 5c piece.

Mr Tripe said the echidna, lyrebird and platypus "have become almost as familiar to New Zealanders as the tuatara, the tiki and the kiwi" on their coins.

"A Reserve Bank survey of coins in circulation has indicated about 5 per cent of those denomination coins - or one in 20 - are foreign, predominantly Australian, which are identical in weight and size," he said.

"Not only do they work in most parking meters and vending machines, shops ... accept them as payment and return them in change."

But when the new, smaller and lighter, coins are issued on July 31, vending machines and meters are expected to be recalibrated to accept the new currency.

Shops will no longer accept the old coins after they are fully withdrawn on November 1.

Dr Tripe said people could find themselves out of pocket as they sorted out jars of coins and took them into banks to exchange.

The Reserve Bank would not exchange foreign coins and trading banks would decide for themselves.

- NZPA