The woman told the Herald the automated message was unacceptable and should be changed.
"They should never at any point say if you don't pay this bill, it could affect your ability to call 111."
"I don't think it should ever be a threat," she said.
The message was effectively saying an overdue bill "may affect your ability to save someone's life," she said.
"I'm more robust than the average person and that shook me. I'd hate to think if it was some 70-year-old woman in an emergency," she said.
The woman also said she had spent about 20 minutes trying to get hold of someone at Spark to speak to about the message.
She gave up after the automated answering service repeatedly told her it couldn't understand her request to "speak to a person", the woman said.
When asked about the message, a Spark spokeswoman said the woman's ability to call 111 would not be affected by an account suspension.
All mobiles phones with battery and reception were able to call 111, she said.
The automated message she received was the same generic message left for all overdue account holders across mobile and land line services.
"In the automated phone call, we do mention to customers that if their account is suspended, it may impact on their ability to call 111."
There was a chance a small amount of landline customers could not access 111 once their accounts were suspended, which is why Spark included the disclaimer, she said.
"We take 111 calling very seriously and this message is purely to make sure customers are aware of the consequences of their account being suspended," the spokeswoman said.
The automated message was left with customers whose bills were more than 40 days overdue. A letter with the same information could also be sent.
Prior to this, customers received their initial bill information, then if needed, a reminder 30 days later that it was still overdue, the spokeswoman said.