WHETHER it's forgetfulness, ungratefulness or a short expiry period, each year in Australia gift cards worth at least $400 million are not redeemed.

Australians spend more than $1.5 billion a year on gift cards.

It is estimated that 20 per cent of gift vouchers are never redeemed. Credit:iStock

It is estimated that 20 per cent of gift vouchers are never redeemed, which means retailers pocket millions of dollars.

While gift cards from some retailers do not expire, those from Coles, David Jones and Myer have a two-year life. Westfield's expire after 12 months. Those of some smaller retailers expire in six months.