I believe the invoice is not correct. How can I check whether my invoice is correct or request a change?

For invoices regarding events, please use our Online Portal:
 

1. You can request a change in the area My invoices.  
2. Select the event in question. 
3. Enter the reason for the change and upload any evidence you may have.
4. Just click on submit form, that’s it! 

To clarify: Invoices for these types of use are not yet stored in the Online Portal.