There are several situations in which invoices are issued without VAT. For example, this may apply to your first trial shift if you did not yet have a VAT ID, if the VAT is reverse-charged, or if you use the Small Businesses Scheme (KOR).
In these cases, the client is required to report these invoices in the annual Uitbetaalde Bedragen aan Derden (UBD) declaration. To identify you correctly, the Dutch Tax Authorities require your BSN.
If you have any questions or concerns, please don't hesitate to contact our support team. We're happy to help!