Bank account for NL company, large volumes

[GPT]

How exactly can a loan agreement be turned into an invoice that too without tax implications. Invoice involves paying sales tax or vat or GST or whatever it's called in the country where sales are shown whereas loan transfers usually are tax free

Tell that to the bank.

Crossborder vat isn’t a problem. Especially not when it’s for services in Europe. So that covers most of the tax issue.

Issue an invoice with a generic description and a unique code. Refer to the code in the loan agreement you don’t share with the bank. Problem solved for the fiscal consequences.

The above is the short version of how this transaction got sorted.