An issue with paying for fuel at outdoor pumps has been confirmed as being related to the leap year.

The extra day in February has affected Allied, Waitomo, Gull and BP truck stops, stopping customers from paying for their gas.

Software provider Invenco was meant to roll out a fix at 3 o'clock - but that hasn't happened.

Waitomo Chief Executive Simon Parham says it's surprising because it's not the first time we've had a leap year.

"I think it's near a base in the software where they've just missed this day, and then the processing couldn't happen."

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