Error 18009

Invalid MerchantOrderItemID. For help on how to proceed, see http://sellercentral.amazon.co.uk/gp/help/30701

This error occurs when we are unable to recognize the MerchantOrderItemID you provided. The MerchantOrderItemID must exactly match a value you previously provided in an order acknowledgment feed. Common reasons why this error may occur include:

• You accidentally provided the AmazonOrderItemID instead of your own MerchantOrderItemID.
• You transposed or omitted characters in your MerchantOrderItemID.
• Your MerchantOrderItemID was never created in the Amazon.co.uk system because of an error in a previous order acknowledgement feed.

1. Review you’re the MerchantOrderItemID field. If the AmazonOrderItemID is in that field, provide a valid MerchantOrderItemID. If the field has a typo, correct this.
2. Update your acknowledgment feed with the corrected MerchantOrderItemID and resubmit your data.