X was obliged under Article 34g of the OB Act at the latest on the fifteenth day of the to issue an invoice every month after the end of that in which the services were performed. It was also established that X had performed the services in the period from February 1, 2016 to March 31, 2018. This meant that VAT had become due in the periods from 2016 to the first quarter of 2018, pursuant to Article 13, paragraph 1, OB Act.
Source: FUTD
