Hello, @Shahab
Welcome to the Docusign Community!
If your envelope still with “Waiting for Others” or “Needs to Sign” status, you just need go to the Manage page, select such envelope then in the option on the right (a little arrow in a dropdown menu) then click on “Void”. The envelopes will be canceled (Voided) and all recipients (signers) will be notified.
Completed envelopes (everybody signed the document) cannot be cancelled (Voided) anymore.
As a suggestion you can ask for your legal department or a lawyer what to do for officially cancel an already signed contract, in general, they will instruct to create a Termination Agreement then send to the previous signers agree with it.
I hope that helps!
Best,
Alexandre
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