Sales Invoices

Due date automatically entered . How to stop this?

You cannot. Various functions require one. So if you don’t enter one, the program enters the current date, meaning “due umm.” Under Form Defaults, you can specify some standard future date.

You could theoretically create a custom theme and prevent the due date being printed on invoices, but AFAIK in most jurisdictions you’re required to have either an explicit payment due date (“due by xx/xx/xxxx”), or a specification of how many days are allowed to pass before payment is expected (“due in xx days”) - without it, it’s not an invoice.