Saasu REST API: Invalid invoice type error

I have developed an integration tool for one of the customers to create a purchase order with invoice type “Money Out (Expense)” in Saasu via REST API. During the synchronization, I received the following error message saying the invoice type is invalid:

 



  
    
      ArgumentException
      Invalid invoice type: Money Out (Expense).
      System.ArgumentException: Invalid invoice type: Money Out (Expense).
   at Saasu.OnlineAccounting.Service.Transactions.Invoices.InvoiceTypeService.Parse(Int32 fileUid, EntityType entityType, String invoiceTypeString)
   at Netaccounts.Ola.Rest.XmlSerializers.InvoiceSerializer.Deserialize(XmlReader reader, Object target)
   at Netaccounts.Ola.Rest.XmlSerializers.Serializer.Deserialize(String xmlFragment)
   at Netaccounts.Ola.Rest.XmlSerializers.InsertInvoiceSerializer.ParseElementData(XmlReader reader, Object target)
   at Netaccounts.Ola.Rest.XmlSerializers.InsertInvoiceSerializer.Deserialize(XmlReader reader, Object target)
   at Netaccounts.Ola.Rest.XmlSerializers.Serializer.Deserialize(String xmlFragment)
   at Netaccounts.Ola.Rest.XmlSerializers.TasksSerializer.ParseElementData(XmlReader reader, Object target)
   at Netaccounts.Ola.Rest.XmlSerializers.TasksSerializer.Deserialize(XmlReader reader, Object target)
   at Netaccounts.Ola.Rest.XmlSerializers.Serializer.Deserialize(String xmlFragment)
   at Netaccounts.Ola.Rest.RestTasks.TasksRunner.Execute(String xmlTasks)
   at Netaccounts.Ola.Rest.Handlers.TasksPostHandler.HandleRequestInternal()
    
  

The first thing that came to my mind is that the invoice type is not supported in the customer region. This can be identified by looking at the Saasu API doc. However, this is not the case. After further studying on Saasu, I found that I need to have the “I am GST registered from” checkbox checked (can be found in Settings -> File Identity). Once I checked the checkbox, the sync just works like a charm 😀