Is PIH mandatory for simplified invoices, or is it optional?

Hello, I’m currently sending simplified invoices to ZATCA. I noticed that even when I send the same PIH value for all invoices (NWZlY2ViNjZmZmM4NmYzOGQ5NTI3ODZjNmQ2OTZjNzljMmRiYzIzOWRkNGU5MWI0NjcyOWQ3M2EyN2ZiNTdlOQ==), I don’t get any error, and I have successfully sent around 40 invoices.

2-Is it possible to delete the current EGS and create a new EGS, then continue sending invoices through the new one?

@ezadeen if you send same PIH in all invoices it is a violation and will be subject to applicable penalties. Not all validations are run time checks, there are backend validations done by ZATCA sequence check on PIH and ICV being one of those backend validations.