In v14:  In the invoice journal >advanced setting > Communication standard(see below for possibilities).

In v12: 

From the Main Dashboard > Applications > Remove the “apps” filter > search for the free module “Belgium - Structured Communication” and install it.

Additional remark: this option is also available standard without installing the belgium module but if allows you to create a payment reference only based on the invoice number or customer.

You obtain a new menu item (so in fact you have 3 different possibilities)

1. Communication based on invoice number

2. Communication based on partner name

3. Structured Communication, which offers you 3 possibilities: random reference,  reference based on invoice creation date, based on internal ref of the partner.

Hi Viviana, thank you for your explanation. 

When I'm looking for this config in v14 and in v15, I don't find the 3 possibilities of Structured Communication you explained.

I just have: 

Communication type: Free, based on customer, based on invoice

Communication standard: Odoo, European, Belgium

And when I choose "based on invoice", I don't see the invoice number or any link to it in the structured communication. This seems to be a random sequence. 

How can I use the Invoice Number in the Structured Communication ? 

Thank you, 

Philippe