The duration varies according to the type of copyright work you own.
Literary, dramatic, musical and artistic works
70 years from the end of the year in which the creator died. Specifically for photographs, or if the works is published after the death of the author, it lasts for 70 years, from the end of the year in which the work was first published.
Published editions of literary, dramatic, musical and artistic works
25 years from the end of the year in which the edition was first published.
Sound recordings
70 years from the end of the year in which the sound recording is first published.
Broadcasts and cable programmes
50 years from the end of the year of making the broadcast or cable programme.
Performances
70 years from the end of the year of the performance.