In Teamleader Focus, invoices and credit notes are generated based on the same template. To access it, navigate to Settings > Document layout > Invoices. Click here for more information how to create templates according to your own house style.

You can choose to only display custom fields on an invoice, a credit note, or both. 

1. To do so, simply add the shortcode for that particular custom field to your template (as you usually do) and define to which document you want to add the custom field. You do this by placing 'Invoice', 'Credit note' or both of them (separated by a comma) between square brackets. Know that this only works for custom fields and not for custom shortcodes or extra shortcodes.
2. To this end, you can use the following short codes:

Custom field on invoice and credit note

$CUSTOM_FIELD_1234[INVOICE,CREDITNOTE]$

Custom field on invoice only

$CUSTOM_FIELD_1234$ or $CUSTOM_FIELD_1234[INVOICE]$
 

Custom field on credit note only

$CUSTOM_FIELD_1234[CREDITNOTE]$