Getting API Programming Error while trying to create Service Request from Repair Orders form

Hi,

I'm trying to create a Service Request for Customer Account # 123, with Bill To address - abc & Ship To address - xyz.

The Bill To address - abc belongs to the same account while the Ship To address - xyz belongs to a different Customer Account # 789.

There is a reciprocal relationship for these two accounts.

I'm trying to create a Service Request & Repair Order but getting the below mentioned error.

API Programming Error (CS_Service Request_UTIL Validate_Bill_To_Ship_ToParty): The value "456" for field ship_to party is invalid.

The value "456" is the party_id of the party number # corresponding to Customer Account # 789.