The Project Lightning network upgrade has added a further 465,000 homes in 2016; a further 800,000 are expected in 2017.
An additional 148,000 customer net additions joined the network in 2016 including 70,000 from new build activity. However, rising churn clipped Q4 net additions back to 31,000.
Customer churn increased from 14.3% in Q4 2015 to 14.8% in Q4 2016.
Virgin is blaming its November price increase for the rise in the number of people quitting the service.
Annual revenues rose by 3% to £4,806 million.