The lax safeguards of payment cards issued to teenage beneficiaries - with the personal identification number printed on the card - have been widely criticised.
The cards, which are being rolled out to about 2600 young people, also require a signature, but that is hardly secure, a security expert says.
Restricted payment cards were introduced as part of the Government's sweeping welfare changes.
Serious questions have now been raised because the Pin for each card is the last four digits of the card number, which is imprinted on the front.
A security expert spoken to by Fairfax Media said signature identification was generally not regarded as enough of a safeguard these days.
The international payment card industry data security standard has strict rules on how Pins should work.
A basic rule is not having the number related to anything on the card.
A spokesman for the Social Development Ministry said the Pin enabled the electronic transfer.
Identity was verified via signature - "with the customer's signature being matched by the vendor with the signature on the card, in the same way that a credit card works".
If the cards were made available to more beneficiaries, the ministry would look at having Pins that clients could change, he said.
The cards can be used only in supermarkets, to pay bills, or where Work and Income quotes are accepted. Alcohol, tobacco and fast food cannot be bought.
Banking expert David Tripe said the verification methods on the cards would not be considered appropriate for bank cards.
Labour's social development spokeswoman Jacinda Ardern said the lack of greater security on the cards was "sloppy".
Pressure on beneficiaries: Page 14
- The Dominion Post
Does more need to be done to protect NZ passports?