Spark is investigating why some customers' text messages are not sending this morning.
"We're aware some people are having problems with texts being delayed or not sending," the company said in a Tweet posted just after 10am.
They said anyone experiencing problems should message them and include their cellphone number, the number and network they are trying to send messages to and the time the message was sent, and if it was delayed, the time it was received by the recipient.
"We'll update you when we know more. Thanks for your patience," they said.