The primary carer will always get a copy of the invoice (even if they are not paying for it). If you wish to set up an additional bill payer, follow these steps:
How to add a secondary bill payer link
If the primary carer does not need to receive a copy, or if you need to set up a new main contact, you can swap the primary carer by following these steps:
Families > Select the current primary carer > overwrite their information with the new primary contact > Save.
All new invoices will now be addressed to the new primary carer.
If needed, you can then change the original primary carer as a secondary carer: