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Joinder: Definition, Example and Related Terms

What is a Joinder ?

A joinder in the business world, simply put, means to join or combine.

Now, you might be wondering why we need such a fancy term for a simple concept like joining or combining. You see, in the world of contracts and legal agreements, joinder has a special meaning. It refers to the inclusion of additional parties or issues in an ongoing contract or legal proceeding. Think of it like inviting more friends to a party that has already started.

Now, you might be wondering why we need such a fancy term for a simple concept like These 'new friends' could be other companies, people, or even new issues that need to be addressed in the contract.

But why would we want to add more parties or issues to an existing contract? Well, sometimes, as the business evolves, we may need to involve more people or address new issues to make sure everyone's rights and interests are protected. This is where joinder comes into play.

It allows us to adapt the contract to changing circumstances without having to start from scratch. However, joinder is not just about adding new parties or issues. It's also about how these new parties or issues are added. There are specific legal rules and procedures that need to be followed to ensure that the joinder is valid and enforceable. These rules and procedures may vary depending on the jurisdiction or the type of contract involved. So, it's always a good idea to get legal advice before attempting a joinder.


  • Scenario Description
    Let's say Company A and Company B are in a contract. During the contract period, Company A merges with Company C. Now, Company C also becomes a part of the contract through a joinder. In this example, a joinder allowed Company C to become part of an existing contract between Company A and Company B. This was necessary because Company A, which was originally part of the contract, merged with Company C. Therefore, to ensure that the contract terms apply to Company C as well, a joinder was used to officially include Company C in the contract.
    Company X has a contract with Supplier Y. Over time, Company X decides to add a new product line that requires different materials. The company wants Supplier Y to supply these new materials, so it decides to add these new requirements to the contract through a joinder. In this case, a joinder was used to add new issues (the supply of different materials for a new product line) to an existing contract between Company X and Supplier Y. This allowed the company to update the contract to reflect its changing business needs without having to negotiate a new contract from scratch.