Vodafone is apologising to Fonterra workers who were mistakenly sent a text message demanding they each pay a phone bill of more than $100,000.
Neither company is able to say how many messages were sent.
Vodafone says human error is to blame for the erroneous text, sent when a new employee in the company's billing department wrongly selected an item in its software system.
A spokesperson says those who were sent the text received another apologising, within an hour.
The message was only sent to Fonterra employees.
The dairy co-operative says it has been told by Vodafone the company has put systems in place to prevent a repeat.