Here's my use case, which I'm guessing might be quite common:
End user visits the site and registers for an event/membership, etc., but rather than pay themselves using their own card/Paypal a/c, etc., they want to optionally provide a purchase order reference and get an invoice that is made out to their employer (or similar), so that the employer can pay the bill.
It feels like the billing block and the invoicing feature are close to being able to meet a need like this, but there doesn't yet seem to be any obvious way to make the required alterations.
What I'm seeing as default behaviour is that the invoice does use the billing address, but not the billing name (it seems to ignore this and use the contact's name instead - which makes me wonder why there is an option to enter a billing name at all, especially as there's no apparent UI to edit it or indeed do anything with it.
And then there's the billing block itself. If I could use a profile of my choosing for the billing block, then I could include the fields I want, such as employer's name, purchase order reference and/or other custom fields, etc. I see there's this Billing Block Adjustment extension (https://civicrm.org/extensions/billing-block-adjustment), which might possibly do the trick. Anyone using that have any advice about what it can provide?
And then, assuming I can get all of that doing what I want, there's the issue of getting the right fields into the invoice layout, which I assume is doable using tokens or similar?
Am I going in the right direction with this, or is there a better way?