That turned out to be almost exactly what happened Bourke.
She had an automatic top-up set up on her card for whenever her balance dropped below $25 but the product manager had recently replaced a broken credit card and said she simply forgot to update the new details on the Hop card.
However, Bourke also wasn't sent any notification that her top-up hadn't gone through and her card was about to be blocked.
Bourke, of Birkenhead, called to complain and an agent was able to transfer her remaining $17 credit on the useless card to another Hop card, which she had to spend another $10 on.
"But then I complained enough that they actually credited me the $10 for the new Hop card but I don't think that would have been normal and they certainly didn't offer to do that."
So infuriated with the process, Bourke fired off an Official Information Act request to find out how many others had gone through the same ordeal.
Since their roll-out in June 2013, 12,124 people have had their cards blocked because of top-up failures totalling more than $330,000 in remaining value - however this figure includes the amount of the automatic top-ups even if the payment didn't go through or whether the customer transferred the value to another Hop card.
Auckland Transport was not able to provide the actual amount of customers' prepaid credit which it's seized.
Spokesman Mark Hannan said three attempts were made to complete Bourke's automatic top-up and admitted a trigger email wasn't sent because there were two email addresses attached to her account and there "was some confusion".
Usually, a customer would be notified of the problem twice before the card is blocked.
The agency is working on an AT Hop website improvement project which includes reviewing the notification process to "improve both the content of the email notification, and the subject, to make it clearer for customers".
They're also looking to provide additional notifications where they were unable to collect payment in an effort to improve the customer experience, Hannan said.
BLACKLISTED HOP CARDS
• Auto reload failures: 12,124 totalling $332,311.62*
• tag on/tag off: 9,486 totalling $79,252.12
• Product abuse: 69 $1,092
TOTAL: 21,679 totalling $412,655.87
*Total includes the reload amount which wasn't able to be processed.
*From June 2013 to July 2016
HOW DOES YOUR CARD GET BLACKLISTED?
• Fare evasion
• Fraudulent use
• Technical fault (auto top-up failure)
• Surrendered card
• Operator request
• Lost / Stolen card
• Damaged card