When you need to update an existing reservation you can use OTA_CancelRQ call.
Request sample
<OTA_CancelRQ xmlns="http://www.opentravel.org/OTA/2003/05" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.opentravel.org/OTA/2003/05 OTA_CancelRQ.xsd" EchoToken="892345" TimeStamp="2003-03-17T09:30:47-05:00" Target="Production" Version="1.001" SequenceNmbr="1" CancelType="Initiate">
<UniqueID Type="14" ID="265913" />
</OTA_CancelRQ>
Required fields:
Version – OTA requires it
UniqueID
Response sample
<OTA_CancelRS xmlns="http://www.opentravel.org/OTA/2003/05"> <Success/> <UniqueID Type="14" ID="265913"/> </OTA_CancelRS>
Response fields explained: