Recently Xero started surfacing the LineItemId for Invoice line items. This is a great initiative. However, to take full advantage of the LineItemId GUID's, we need the ability to send our unique LineItemId's on a PUT.

Assuming that we could to specify our LineItemId (and that it would be contained in the Xero Response) we would then have the certainty required to associate the Xero LineItemId response with our LineItemId's.

This feature enhancement is critical as our invoices always have multiple LineItems, often with the same quantity and Amounts.

We need a way to ensure we are able to match the LineItems on each side.