Where do I enter the IBAN number of my company bank account?

Step 1) Click on the "Settings" button at the top right of the page.
Step 2) Click on the "Company Details" column at the top left of the page.
Step 3) Click on the "Additional Company Details" button at the top of the page.

Step 4) Enter your IBAN number and don't forget to click the "Save" button at the bottom right of the page.