"Vodafone call centres nationwide which were impacted by a Penrose fibre cut this morning are now taking customer calls," it said in a statement.
"Vodafone self-service tools, including My Vodafone, are also back up and running."
However, because of the earlier cut, customers were warned to expect "long call wait times".
The company "sincerely apologises" for the inconvenience to customers.
Vodafone's network was unaffected by the cut, with mobile, fixed and business services running as normal.
Lines company Vector said the fibre cable had been cut by a third-party contractor shortly after 11am today.
The contractor also damaged a gas pipe, leading the Fire Service to take control of the site until the pipe was repaired at 3.36pm.
Vector spokeswoman Sandy Hodge said fibre crews then went in and made repairs.
"Initially, it was thought the repairs could take until 10pm, but crews have managed to restore earlier."
Vector said contractors must take care when digging around other utility services, and the company would be investigating today's incident thoroughly.