In January, the company said it was on track to launch commercially during the first half of the year.
Orange is currently trialling the IPTV technology with 300 of its customers across London and Leeds. However, the firm is believed to be experiencing technical difficulties implementing the service across its fixed-line network, which is causing the launch delay.
A spokeswoman for the communications company said: "Orange's home digital TV service is scheduled for a UK roll-out this year. The exact date will depend on the outcome of ongoing trials and the feedback from Orange's customers."
The development of Orange TV is being headed by Tim Pearson, director of IPTV at the group. Last year, Pearson told Media Week that the company was looking at offering clients the ability to run campaigns across its broadband, TV and mobile platforms.
Orange has so far signed content deals with Disney-ABC International, which will give subscribers to the service access to films from Disney, Touchstone and Miramax, and MGM, which will give its customers access to movies made by the studio, such as Silence of the Lambs, Four Weddings and a Funeral, Platoon and Rocky.
The spokeswoman added that Orange had a number of other agreements in place.