Telecom has blocked a bid by emergency services to trademark the emergency number 111.
Police, the Fire Service and St John jointly tried to register 111 as a trademark with the Intellectual Property Office.
If successful they could have barred people from using the number 111 on goods and services, including vehicle licence plates or in education and advertising.
But assistant commissioner of trademarks Jenny Walden refused the application after opposition from Telecom, which provides the 111 service, the Dominion Post reported on Friday.
Ms Walden agreed with Telecom that trademarking 111 would cause public confusion and unnecessary worry for business owners.
A trademark had to be used in trade, and the police and Fire Service were not commercial traders, she said.
There was also the possibility that people would not phone 111 in an actual emergency, because they would think they would be charged, she said.
"This confusion could lead to serious consequences."
Police Assistant Commissioner Viv Rickard said they had sought the trademark to prevent businesses cashing in on the 111 number.
"We feel sure that the public wholeheartedly believes 111 should be vested with the emergency services of New Zealand, rather than any commercial entity," he said.
A Telecom spokeswoman said it was comfortable with the decision. Telecom had opposed the trademark because it would have made it difficult for the company to do its job as a telecommunications provider, she said.
"If it was trademarked, we feel the application should include Telecom as well."
Telecom tried to trademark the number in 1994, but the bid was abandoned after four years.
NZN