Consumer NZ wants people to be aware of their rights when returning and exchanging gifts.

The Consumer Guarantees Act does not require a retailer to give a refund if a person buys something and then changes their mind about it.

But Consumer NZ spokesperson Jessica Walker says some stores have generous returns policies.

Consumers would need either a receipt or proof of purchase, she says.

"You can't just rock up at a store and say 'hey, I think that somebody bought this from here and I want to return it or exchange it please' because obviously that's not fair on the retailer."

The consumer watchdog also warns people against adding extended warranties to their purchases when hitting the sales this season.

The Consumers Guarantees Act affords people enough protection, says Jessica.

"With an extended warranty, most of the time you're actually getting less protection or equal protection to what you've already got under existing law ...

"That means that if your good develops a fault pretty quickly, then you are entitled to get it repaired, to get an exchange or, if the fault is catastrophic, to get a full refund - it should last longer than the manufacturer's warranty as well."

Jessica says if something didn't work, consumers are entitled to a refund, even if it was bought on sale.

-RNZ.