OTA_HotelResRQ direct sell fails with FORMAT ERROR ON OPTIONAL FIELD - sabre

Question

I'm making the following sequence of calls to reserve a hotel room using the direct sell request:
HotelPropertyDescriptionRQ
PassengerDetailsRQ
OTA_HotelResRQ
The final response errors with:
FORMAT ERROR ON OPTIONAL FIELD
I'm unable to work out what is causing this error - is it perhaps the RPH of the room is not being correctly added to the PassengerDetailsRQ?
The OTA_HotelResRQ is:
<OTA_HotelResRQ xmlns="http://webservices.sabre.com/sabreXML/2011/10" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ReturnHostCommand="true" TimeStamp="2017-02-13T12:45:24" Version="2.2.0">
<Hotel>
<BasicPropertyInfo RPH="001">
<ConfirmationNumber>PWBA-POW-131c-02</ConfirmationNumber>
</BasicPropertyInfo>
<Guarantee Type="G">
<CC_Info>
<PaymentCard Code="VI" ExpireDate="2018-10" Number="4111111111111111"/>
<PersonName>
<Surname>TEST</Surname>
</PersonName>
</CC_Info>
</Guarantee>
<RoomType NumberOfUnits="1"/>
</Hotel>
The HotelPropertyDescriptionRQ:
<HotelPropertyDescriptionRQ Version="2.3.0" xmlns="http://webservices.sabre.com/sabreXML/2011/10">
<AvailRequestSegment>
<GuestCounts Count="1" />
<HotelSearchCriteria>
<Criterion>
<HotelRef HotelCode="0007855" />
</Criterion>
</HotelSearchCriteria>
<TimeSpan End="2016-12-17" Start="2016-12-10"/>
</AvailRequestSegment>
</HotelPropertyDescriptionRQ>
The PassengerDetailsRQ:
<PassengerDetailsRQ xmlns="http://services.sabre.com/sp/pd/v3_3" version="3.3.0" IgnoreOnError="false" HaltOnError="true">
<PostProcessing IgnoreAfter="false" RedisplayReservation="true" UnmaskCreditCard="true">
<EndTransactionRQ>
<EndTransaction Ind="true"></EndTransaction>
<Source ReceivedFrom="PW TESTING"/>
</EndTransactionRQ>
</PostProcessing>
<PreProcessing IgnoreBefore="false">
<UniqueID ID=""/>
</PreProcessing>
<SpecialReqDetails>
<AddRemarkRQ>
<RemarkInfo>
<FOP_Remark>
<CC_Info Suppress="true">
<PaymentCard Code="VI" ExpireDate="2017-12" Number="4444333322221111" SuppressApprovalCode="true"/>
</CC_Info>
</FOP_Remark>
</RemarkInfo>
</AddRemarkRQ>
</SpecialReqDetails>
<TravelItineraryAddInfoRQ>
<AgencyInfo>
<Address>
<AddressLine>XXXXXXXXXXX Ltd</AddressLine>
<CityName>London</CityName>
<CountryCode>GB</CountryCode>
<PostalCode>XXXX XXX</PostalCode>
<StateCountyProv StateCode="LN" />
<StreetNmbr>2 Some Rome</StreetNmbr>
</Address>
</AgencyInfo>
<CustomerInfo>
<ContactNumbers>
<ContactNumber NameNumber="1.1" Phone="817-555-1212" PhoneUseType="H" />
</ContactNumbers>
<PersonName Infant="false" NameNumber="1.1">
<GivenName>Iain</GivenName>
<Surname>TESTING</Surname>
</PersonName>
</CustomerInfo>
</TravelItineraryAddInfoRQ>
</PassengerDetailsRQ>

Answer 1

I believe it is because you are adding a confirmation number to the sell request, which is an optional field when selling passive segments, but it should not be expected when actually requesting the room to the hotel.
<ConfirmationNumber>PWBA-POW-131c-02</ConfirmationNumber>
I would try removing that.

Answer 2

To reserve a hotel room using the direct sell request from sabre used OTA_HotelResRQ request.
Here is one example for request (i already used this request and get response from sabre)
<?xml version="1.0"?>
-<OTA_HotelResRQ Version="2.2.0" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-<Hotel xmlns="http://webservices.sabre.com/sabreXML/2011/10">
<BasicPropertyInfo RPH="001"/>
<Customer NameNumber="01.01"/>
-<Guarantee Type="G">
-<CC_Info>
<PaymentCard Number="3782 8224 6310 005" ExpireDate="2021-09" Code="AX"/>
-<PersonName>
<Surname>tailor</Surname>
</PersonName>
</CC_Info>
</Guarantee>
<RoomType NumberOfUnits="1"/>
</Hotel>
</OTA_HotelResRQ>