The terms and conditions of the basic contract specify performance requirements for task or delivery orders issued under the IDIQ. The contract may state something like “The Contractor work shall commence work only after issuance of the task order by the Contracting Officer.” It’s a best practice for the CO to require the contractor’s signature to acknowledge the terms of the orders. However, unless the contract so specifies, contractors are not required to sign orders; they can begin performance once they receive the order. If the contract does in fact requires signatures, the contracting officer may consider modifying the contract to remove that requirement if desired.