Sky Go customers are complaining of being unable to use the app to stream channels during three big sporting events.
It has been out of action as the Black Caps play Pakistan, during the rugby Sevens in Wellington and Ultimate Fighting Championship (UFC) screenings.
The app allows customers to screen Sky channels when away from their televisions.
Sky has said on its Facebook page: "Our tech teams are still working to resolve the issue with SKY Go login. I'll update you as soon as I have any developments. Sorry for the interruption to your Sunday online viewing."
Customers vented their frustration on the page.