This summer, Simon Dierl contributed Invoice2 to TeX/LaTeX, to easily create typeset invoices with automatic VAT and calculation of totals. Here is a makeshift way to change one of the defaults.
Invoice of 'Société de Photographie Mayer Frères & Pierson', to 'Mr Le Général de Ponteres', for 51 Francs, dated 1856, and signed by Mayer and Pierson (Public Domain Marked)
Internationalisation for Invoice2 is provided by the Translations package. In Invoice2, Simon already provides the defaults for German and English.
Suppose you want to send an invoice to a Dutch client, using a column heading 'Prijs', instead of the English default 'Price'.
In the pre-amble of your LaTeX document, add: