The Oklahoma Notice of a Lawsuit and Request to Waive Service of a Summons (AO-398) is a legal document issued by the court to a defendant in a civil case. This notice informs the defendant of the lawsuit and requests that they waive service of the summons. The defendant must sign and return the notice of waiver within twenty days of receipt. There are two types of Oklahoma Notice of a Lawsuit and Request to Waive Service of a Summons (AO-398). The first is the Notice of Lawsuit and Request to Waive Service of Summons served on an individual. This notice informs the individual of the lawsuit and requests that they waive service of the summons. The second type is the Notice of Lawsuit and Request to Waive Service of Summons served on a corporation. This notice informs the corporation of the lawsuit and requests that they waive service of the summons. The Notice of Lawsuit and Request to Waive Service of Summons must be signed and returned within twenty days of receipt. If the defendant waives service of the summons, they are acknowledging that they have been informed of the lawsuit and are giving up their right to be formally served with the summons. If the defendant does not waive service within twenty days, they may be subject to additional costs and fees.