### Clue: Backing up computer work, rest­oring deleted spread­sheet, initially for owners' documents (5,5)
### Answer: TITLE DEEDS 
 ### Explanation: Definition: owners' documents
A charade of TI, a reversal ('backing up') of IT ('computer work') plus TLEDEED, an anagram ('restoring') of 'deleted' plus S ('**S**preadsheet initially').