The number of services in operation fell by 62,000 to 36.2 million for the six months that ended in June, Telsyte said in a statement on Tuesday.
This meant a fall of 4% in mobile services revenue which was $13 billion for the FY2020.
The Telsyte Australian Mobile Services Market Study FY2020 tracks mobile services in operation, including handsets, mobile broadband and mobile IoT for business applications.
"Telsyte estimates there were around 4.4 million mobile IoT services in operation at the end of June 2020, up 8% from December 2019," the statement said.
Telsyte found that the MVNO segment had strong growth during the six months, reaching almost 16% of services in operation at the end of June, an increase of 2% from the previous financial year.
Among the big telcos, Optus and TPG Telecom took a beating while Telstra retained its market share due to a strong showing in the mobile IoT space.
Telsyte said it expected the total number of handset SIOs would remain at similar levels during the next 12 to 18 months.
"Consumers are set to be the big winners in the next 12 months as mobile service providers battle it out with attractive offers," Telsyte senior analyst Alvin Lee said.