By default, a sales order's primary contact will be set as the billing contact for any invoices raised from that order.
Alternatively, it's possible to configure Billing Type contacts. This means that specific contacts can be set as a billing contact by default.
A contact's type can be viewed or changed on the Contacts tab.
A contact with type Billing will be assigned as the invoice contact by default. There are a few caveats:
If the customer record has multiple contacts of type Billing, no contact will be auto-assigned unless one (and only one) of them has the PRI (primary) checkbox ticked.
This is to avoid auto-assigning a contact when there is some ambiguity as to who should be assigned.
If you use Customer Sites, a contact will only be assigned to the invoice if they are assigned to the invoice's site.
The Contact Type is shown in brackets next to each user's name in the drop-down menu on an invoice record.
Configuring Billing Contact Types
Contact types can be defined in Settings - Contact Types. The Billing Type flag must be enabled for that type for contacts to be be auto-assigned to an invoice.
Enabling the feature
To activate this logic, an administrator must check the Respect Contact Types for Invoice setting under Settings - Company Setup - Customisations.