You sure can, but you’ll need to edit the code directly as the PDFs are generated using the opensource FPDF library, so the documentation on the FPDF website should be your first read. Read through that for an overview of what goes on under the hood.
Basically, there are 2 files which control the output of the PDF for invoices and 2 files which control the output of the PDF for quotes. There are two files for each as one controls the output for your own ‘View In PDF’ option and one is for the PDF that is generated when you email it to a customer.
So for the invoices, the first file you should edit is found at:
In here. if you scroll down you’ll a section comment like this:
// Create PDF
In there you will find the strings/text, images etc that you will want to edit.
If you want to know a little more about what each of these line of code is doing, and what other options you have, maybe check out the FPDF Manual.
The second file is:
Scroll to the email function (line 221) and in there you’ll see a similar layout (under the // Create PDF comment) as before. Make the changes you need there too.
That’s it for invoices and the quotes can be manually changed in the same way. The files for this are:
Remember though, you are manually changing these files and that may be an issue when we release updates in future as if these files are changed by our update then these files may be overwritten. For that reason, it would make sense to keep backup copies of these files (and any others that you edit) for backup and reuse later.