Customize the sales invoice heading

Is that any way we can customize the print heading of the sales invoice, Not like purchase invoice or Sales quote, it gives the complete heading, when we print.It says only “Invoice”, will be helpful, if we can customize to “Sales Invoice” or “Proforma Invoice”. Tnx

You can customize your theme if you have html knowledge. else you can hire someone locally to do it for you.
read this guide

When an in-built tax code is selected, the title automatically changes to Tax Invoice.

a sales invoice and proforma invoice are not same. enable and use Sales Quotes for making proforma invoice.

@sharpdrivetek, well noted, thanks for your guidance. Appreciate it