Hi VT3,
Got it—you're looking for accurate invoice sequencing and filenames that match your preferences. As for the invoice number sequencing, you may check out this thread, it works the same with MYOB Business Pro.
Currently, the system adds "Invoice-" to filenames by default when emailed or downloaded. I know that’s not ideal, so I’d suggest posting in our MYOB Business Idea Exchange. This way, our developers can consider it for future updates.
Feel free to get in touch if there's anything else I can assist you with.
Cheers,
Princess