Telstra Corporation is estimating that more than 1000 of its services in the Top End could go down over the next few weeks.
The company's Brian O'Keefe says stormy weather has already damaged about 200 fixed phone lines around Darwin and Palmerston.
He says there could also be delays in fixing the faults because of a lack of staff.
"We're just under a lot of pressure in terms of maintaining our network at the moment," he said.
"With all these extreme weather events, we haven't had the normal help that we get from down south and we've had to make do with our normal Territory staff."
Mr O'Keefe says he expects the number of services affected to greatly increase.
"Just rain and water getting into our cabling really is the issue," he said.
"And we've also had a few issues with lightning hitting our equipment which also causes damage."
© ABC 2013
20:42 EDT Railway operator Metro Trains has cancelled dozens of services as Melbourne braces for extreme heat on Thursday.