By John Ostapkovich

PHILADELPHIA (CBS) – The fact that American Express has decided to stop selling its gift cards at New Jersey retail stores is the latest salvo in an ongoing battle over what happens to un-redeemed card values.

There are holiday-season stories every year about merchant policies on gift cards values if not totally used up, but a New Jersey law might trump that. It gives the state the right to that money after two years.

The law is being challenged in court by the New Jersey Retail Merchants Association, among others.

“We’re not required to do anything just yet,” says the group’s president, John Holub. “We’re still waiting for guidance from the state on how they intend to implement this law, but we’re fearful that they’re going to require any retailer to collect the zip code from anyone purchasing a gift card.”

Holub says that requirement is a deal breaker.

“No other state in the country would require retailers to collect the zip code and because of that we don’t have the IT infrastructure and it isn’t as simple as buying something off the shelf, because it doesn’t exist.”

An injunction against zip code collection was lifted last month and Holub suspects AmEx got out ahead of enforcement to avoid its hassles.