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The premise behind the SendInvoice call is that the ShippingAddress that the buyer has indicated for the transaction or order is known.
As a result, the expectation is that the shipping services indicated in the SendInvoice call apply only to the ShippingAddress of the buyer.
Unlike the AddItem call which listed the item, the SendInvoice call should not send in all shipping services for the item.
The only shipping services that should be included in the SendInvoice call are ones that are valid for the buyer's shipping address for the transaction.
This means that if the shipping address is international with respect to the item, then there should be no domestic shipping services indicated in the SendInvoice call.
If the shipping address is domestic, then there should be no international shipping services indicated in the SendInvoice call.
This is distinctly different than the AddItem call requirement which stipulates that in order to have international shipping services, the call must indicate at least 1 domestic shipping service.
This requirement on the AddItem call does not apply to the SendInvoice call.