How to customize the invoices layout
All the invoices are generated through a Template File that can be customized from the Configuration page, 3rd tab, by clicking on the Edit Template File next to the row called 'Invoices Template'.
At the beginning of the file you will find some PHP comments that define some default parameters for the PDF generation such as Margins, Page Format, Page Orientation, Font Size, Header, Footer etc.. Make the necessary changes to the default parameters to modify the layout of the invoices.
If you wanted to modify the HTML structure of the invoices, then you should work on the last part of the same Template file where you will find a few HTML Table tags. Please notice that the HTML Source Code of the Invoices Template File cannot be like a web-page. This is because the DOM Document Class used to convert HTML into PDF contents, is not a browser. CSS definitions and Classes are not accepted, you should use inline HTML attributes.
Please notice that by making some changes to the Invoices Template File, the invoices already generated will not be modified as those are files saved on the server. In order to test the modifications made, it is necessary to create or re-create some invoices from the back-end (Bookings - All Bookings page).