This is not true, you can have different tax codes determined for a single country.
In standard for domestic sales you use customer tax classification and material tax clasification to determine different tax codes for example for FG products and for services, for customers with full VAT or without VAT or with different VAT.
You can also create access to add to the standard sequuence for order type or billing type for domestic sales - e.g. Country/Dest.country/Tax.classification customer/Tax classification material/Billing type.
Of course you have to ensure to post to the correct accounts by setting up the tax procedure and the tax codes.