"Our tech teams are urgently investigating and repairing a nationwide issue impacting some mobile data services," Vodafone said in a statement.
"Some customers are experiencing an intermittent loss of 4G internet connectivity, which we believe is impacting PostPay (on account) customers only.
At 8.21pm, the company said in an update on Twitter that the issues had been sorted.
*Update 08.21pm: Thank you for bearing with us everyone – all issues affecting mobile data services are now resolved, and will continue to be monitored.