Hi there, @Giulio.

I'm here to help ensure you're able to accept multiple transactions with different currencies. 

You can utilize the Multi-currency feature to help you manage them in QuickBooks. Please note that this feature is only available in the Essentials, and the Plus versions.

Here's how:

1. Go to the Gear icon at the top, then select Account and Settings.
2. Choose Advanced on the left panel.
3. Click on the Pencil icon for Currency, then select Home Currency.
4. Mark the box for Multi-currency.
5. Click on Save and Done.

Since you’ll be accepting Euro and Pounds, ensure you create these customers and banks in QBO to efficiently track transactions for each currency. Here's how:

To add customers

1. Go to Sales on the left panel, then choose Customers.
2. Click on the New customer button.
3. On the Customer Information window, enter the information for your UK agency/ EU client. Then click Save.

To add the foreign currency accounts

1. Go to the Gear icon at the top, then choose Chart of Accounts.
2. Click on New in the upper-right hand, then choose the correct Account and Detail Types.
3. Enter the account’s name in the Name field.
4. Under Currency, click on the drop-down and choose GBP British Pound Sterling/EUR Euro.
5. Click on Save and close.

Once done, you can now create invoices and accept payments in Euro. Then, transfer the funds from your EU account to the GBP bank.

The information I provided should point you in the right direction.

If you have additional questions about QBO, reach out to me by posting a comment below. I'm here to assist you further.