Hello,

In Belgium we often pay invoices with a structured payment reference, for example:
+++123/1234/12345+++
It's always the same structure: +++xxx/xxxx/xxxxx+++
This is made for each invoice with a formula.
In CRM we can create custom fields with formula, but in Books I can't find it.
Is it possible to add a formula field in the template field for invoices or somewhere else
so that on each invoice a specific payment reference is created due to this formula?