No Order detail tax row when tax amount is zero

[d0ma]

Hallo,

i developed a module to transmit order data to an external Software(Sage Start).

Everything worked perfect until our client added a order(BO) with one product Price being zero. In this case Prestashop does NOT save an order-detail-tax row. Most likely because whatever tax * 0.0 is zero.

I always need to transmit an VAT code to the external software, even  if the product price is zero.

Any ideas how to retrieve the tax_id of the order-detail in this case? Or better to force prestashop to Save the order-detail-tax line even if the tax amount is zero?

best regards,

d0ma