The structure to report the Equivalence Surcharge depends on whether the party under this regime is your customer (the issuer) or the invoice recipient.
If it is your customer who is under the Equivalence Surcharge regime, you must use "EQUIVALENCE_SURCHARGE" in system.type. For example:
{
"text": "Product A",
"quantity": "2.00",
"unit_amount": "100.00",
"full_amount": "193.60",
"discount": "20.00",
"system": {
"type": "EQUIVALENCE_SURCHARGE",
"category": {
"type": "VAT",
"rate": "21.00"
}
}
}If, on the other hand, it is the final customer (invoice recipient) who is under the Equivalence Surcharge regime, then don't use "EQUIVALENCE_SURCHARGE" in system.type, but instead use the additional_vat field inside category:
{
"text": "Product A",
"quantity": "2.00",
"unit_amount": "100.000",
"full_amount": "201.92",
"discount": "20.00",
"system": {
"type": "REGULAR",
"category": {
"rate": "21.00",
"type": "VAT",
"additional_vat": {
"rate": "5.20",
"amount": "8.32"
}
}
}
}
In this second example, the calculations are:
Taxable base of the item:
(unit_amount - discount) * quantity(100 - 20) * 2 = 160Surcharge 5.2%:
160 * 0.052 = 8.32VAT 21%:
160 * 0.21 = 33.60full_amount:160 + 8.32 + 33.60 = 201.92