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Collateral relatives: Definition, Example and Related Terms

What are Collateral relatives ?

Collateral relatives might sound like a term from a detective novel, but it's simply a name for family members who are related to you, but not directly. They come from a common ancestor, like the trunk of a family tree that splits into various branches.

Think of your parents as your 'direct' relatives. They are like a straight line on the family tree from you to them. But, if we move sideways across the tree, we can find a whole group of other relatives. These are your collateral relatives. Some examples include cousins, aunts and uncles who are not directly in line with your descent but are still connected through common ancestors, like your grandparents or great-grandparents.

Although the term 'collateral relatives' may not appear in contract law often, it's good to understand the term as it can come up in other legal documents, such as wills or trusts.


  • Collateral Relative Description
    Cousins Common grandparents
    Aunt (paternal) Father's sister
    Uncle (maternal) Mother's brother
    Niece Sister's daughter
    Nephew Brother's son