Causes
- You have entered two VAT codes of the same type (VAT due or deductible VAT)
- You have entered two VAT codes with different rates. If the transaction involves different rates, please refer to the documentation on Reverse charge in the section Reverse charge with different rates
Solutions
- Set one of the two codes to VAT due and the other to deductible VAT
- Check that the two VAT codes are complementary
- Use two codes with the same VAT rate and the same parameters
For more information on Reverse Charge, see the page: VAT entry with reverse charge.