Telstra is the most popular mobile service provider in four out of five of Australia's capital cities, with Sydney being the only exception.
According to Roy Morgan Research, Vodafone was the most popular mobile provider from July to December 2016 with 30.4 percent market share, compared with 27.9 percent for Telstra and 26.5 percent for Optus.
For all five capital cities, Telstra maintains a 43.6 percent market share followed by Optus with 24.1 percent and Vodafone with 18 percent.
As the largest city in the country, Sydney is also the most competitive for telcos, with just 50,000 customers separating Vodafone and Telstra.

Roy Morgan Research chief executive Michele Levine said the Sydney mobile market was worth more than $2.6 billion to the three biggest network operators, who control 83.3 percent of the market.
She said that there might be a simple explanation for why Sydney differs from the rest of the country: Vodafone has a much larger brick-and-mortar presence in New South Wales.
“Roy Morgan’s analysis indicates that traditional retail reach is an important piece of the puzzle. Almost three in five mobile owners in Sydney purchased their current mobile plan from a store, which is the same proportion as in Melbourne, where Vodafone is a distant third," she said.
“Vodafone’s share of owners and their dollars in each city is actually remarkably similar when looked at ‘per store’. That is, while mobile owners in Sydney and Melbourne equally prefer to buy their plans in-store, Vodafone has just over 50 percent more stores in Sydney - so it is any wonder its share of the market (and revenue) is also just over 50 percent higher?"