I'm glad to know that your business is growing, Jens Pen.
At this time, only US addresses and SSNs are allowed when adding contractors in QuickBooks Online. However, you can pay internationally by integrating a third-party vendor. With this, you'll get to manage your expenses accordingly.
In addition, I've added an article in case you want to know who needs 1099s, payment totals, and more: Create 1099 reports in QuickBooks.
Don't hesitate to come back to this thread if you have other concerns about managing contractors in QuickBooks Online. The Community is here to assist you. Take care!