Is there a possibility to have outgoing invoice with two currencies, one in Eur and USD parallelly? Thanks

Welcome to the Community, @visionstack-prot.

I'll share some information about using multi-currency in QuickBooks Online.

You can add one customer per invoice. You can also assign one currency per customer. That said, creating one invoice with multi-currency is not possible.

You can assign another currency to a customer by adding a new profile. Then you can create another invoice for that new profile.

Here's how:

1. Select the Sales menu at the left panel and then choose the Customers section.
2. Click the New customer button.
3. Fill up the Customer Information window.
4. Click on the drop-down under Currency, and choose the correct one.
5. Click Save.

You can also review this article for more information about the process: Assign a foreign currency to a customer in QuickBooks Online.

I'm also adding this article as your reference for managing invoices in QuickBooks Online. It also includes links on how to process and track payments.

If there's anything else I can help you with managing your invoices, I'm happy to help you further. Enjoy the rest of the day.