A supermarket worker sacked over non-payment for a loaf of banana bread says the action had "ruined my life".

Janice Taylor was stunned to be fired from her job as a supervisor at Manurewa's New World Southmall because of the issue with the $5.95 loaf, which she said she simply forgot to pay for.

But her employers saw it differently; describing her actions as a deliberate breach of staff rules, and dismissing her for "serious misconduct".

In a recently-released decision, the Employment Relations Authority (ERA) sided with the supermarket owners, finding Ms Taylor's dismissal was justified.

Since being fired, Ms Taylor has taken up a part-time supervisor role at another Auckland supermarket, but says she is struggling from the effects of being fired and the ERA's decision.

"I think it's grossly unfair. This thing did not warrant dismissal," said Ms Taylor, who said she had "absolutely" planned to pay for the loaf.

"It's ruined my life."

Ms Taylor has been relying on family for financial support since losing her job as she had not been able to find full-time work, she said.

Her former employer Kym Samuels was pleased with the ERA decision.

"I was relieved that my process was intact, and that I had been seen to be fair in the judgement that I had made at the time."

"This kind of conduct is not uncommon in our industry, and there has been a number of other staff in our store in a very close period of time that has had similar outcomes," said Ms Samuels.

The incident started on the morning of January 6 this year when Ms Taylor, who has 15 years' experience working in supermarkets, was phoned by Robyn, a regular customer, with her grocery order.

As she is blind, the customer would ring through her order each week and then come into the store to collect and pay for the items.

That morning, Mrs Taylor put together Robyn's order as usual and while doing so "decided to put a loaf of banana bread into the order as she thought it would be nice to gift the bread to Robyn who she knew liked bananas and might like this new product", said the ERA finding.

Ms Taylor, who was known as a "stickler for the rules", intended to pay for the bread herself and give it to Robyn, the finding said.

She took the items to the checkout to be scanned by a checkout operator, but when she got to the banana bread, told the operator to put it through without scanning it.

She admitted this breached staff purchasing procedure, which states workers buying items must do so through another operator and no IOUs are allowed.

The bread was packed in with Robyn's groceries, which were collected shortly afterwards.

In the finding, Ms Taylor said she did not pay for the bread at the time because she didn't have any cash on her. She then planned to get some money during her break but was distracted when she was called back to the supermarket, as a kitten was loose inside.

It wasn't until she was called into a meeting with supermarket owner Ms Samuels four hours later that Ms Taylor remembered she hadn't paid for the bread, said the finding.

After an investigation, her employers found Ms Taylor guilty of serious misconduct, and she was dismissed on January 9.

Ms Taylor appealed the decision, but ERA member Anna Fitzgibbon agreed with her former employers, saying she knowingly breached the rules and finding her dismissal to be "fair and reasonable".

"The breach was deliberate, went to the heart of the employment relationship and amounted to serious misconduct for which dismissal was justifiable.

"Even though Ms Taylor says she intended paying for the banana bread, Ms Taylor did not," said Ms Fitzgibbon.

Ms Taylor started working as a night supervisor at New World Papatoetoe six months ago.

Her new employer, store owner Max McDermid, said he was aware of the issue with Ms Taylor's previous employer when he hired her, and he has had no disciplinary issues with her.

- APNZ