Standard rate (S): no exemption reason allowed

What does this error mean?

A VAT breakdown of category S (standard rated) must not contain an exemption reason (BT-120/BT-121) — taxed and exempt at once is contradictory.

How to fix it

Remove the exemption reason — or, if the supply really is exempt, change the category to E/AE/K/G.

Affected fields

• BT-120 VAT exemption reason text
• BT-121 VAT exemption reason code
• BG-23 VAT breakdown

← All validation rules
Rule source: EN 16931 / XRechnung (KOSIT) or Billhorse check (BH-*).