Changing the name on your invoices, so the next invoice will be sent to your employer instead of you, can be handled by yourself in the E-Flux Dashboard. Just click 'profile & Settings' in the bottom left corner and then click 'Billing' in the menu on the top and edit your payment details.
If you have already received an invoice which was supposed to be received by your employer you can best declare the invoice with your employer. We can also edit the existing invoice to display your employers details, but this action requires a service charge of €12,50 excl. VAT.