The telco said its previous FY20 guidance provided on 15 August was based on the NBN Co's corporate plan for 2019, assuming that the NBN rollout and migration in FY20 would be in line with that plan.
But the latest NBN Co corporate plan cut the number of premises forecast to be connected in FY20 by 500,000, from 2 million to 1.5 million.
"This change materially impacts the guidance Telstra provided on total income, underlying EBITDA and the amount of included in-year NBN headwind, net one-off DA receipts less NBN net cost to connect and free cashflow after operating lease payments," the Telstra statement said.
Under an agreement reached with the NBN Co, Telstra is paid for each customer who moves from its network to the NBN. Under the changed corporate plan, Telstra will receive $300 million less in NBN Co payments during FY20.
Telstra has revised its total income for FY20 from $25.7 billion to $27.7 billion to $25.3 billion to $27.3 billion, a drop of $400 million. Underlying EBITDA has been revised from $7.3 billion to $7.8 billion to $7.4 billion to $7.9 billion, an increase of $100 million.