An addendum is a document that is added to an existing contract or agreement, usually at the time of signing. It serves as an amendment or supplement to the original contract and is used to clarify, modify, or update the terms of the agreement. When adding an addendum, it’s important to ensure that both parties agree to it; this is typically done by having both parties initial or sign the document as a way to give it legal standing. By incorporating an addendum into an existing contract, you can ensure that all parties involved are on the same page, which is beneficial for everyone involved.