Telstra services have been restored in Bilpin and Mt Tomah after a severed cable saw telephone and internet services to the area go down for about 16 hours.
The cable was cut by a contractor not related to Telstra doing excavation for a third party in Richmond about 9.30am on Tuesday, July 23.
"An optic fibre cable cut by a contractor working near Richmond yesterday morning (July 23) impacted the operation of four mobile base stations and up to 1,100 landline telephone services and 2,300 ADSL internet services to residents and businesses in the Kurrajong Heights and surrounding areas for approximately 16 hours," Telstra's regional general manager for NSW Mike Marom said in a statement.
"Telstra crews worked until the early morning to facilitate repairs, with almost all services back on line by approximately 2am today (Wednesday, July 24).
"The remaining 140 impacted fixed lines services at Berambing were restored by Telstra technicians later that morning.
"Telstra thanks residents for their patience while repairs were underway."
Telstra has encouraged people to use the Dial Before You Dig service before commencing any ground breaking activity to avoid damaging underground infrastructure.
Any Telstra customers still experiencing issues should contact 13 2200 to report a fault, the statement said.