Most school children use mobile phone text messaging to chat with family and friends but an increasing number of kids are using it to bully others.

The parents of Oamaru teen, Daniel Gillies, who committed suicide two and a half years ago believe text bullying may have contributed to his death.

Vodafone has now put measures in place to ban bullies from using its network.

Children who have received derogatory or threatening texts on their phones have reported the bullying to counselling groups like Netsafe.

"Because mobile phones are such an integral part of young peoples' lives - they have them with them all the time - so the bullying is relentless," said Netsafe's Liz Butterfield.

Lynley Kirk-Smith from Vodafone said the network is taking the problem seriously.

"What we're able to do is to take a complaint, investigate it, then depending on the seriousness or the content, we're able to bar a customer from our network," Kirk-Smith said.

Vodafone is backing a campaign to put out brochures and posters at schools nationwide.

Butterfield is encouraging victims to report any bullying.

"They just need to tell somebody, a trusted adult in their lives, and then steps can be taken and they can be protected," Butterfield said.