If you need to issue a credit note that applies to multiple invoices, you must include the reference_transaction_id as part of the line item that shows the adjusted values related to a previous invoice.

In this scenario, you should not send the reference_transaction_id at the invoice level, but only within the line items. Each item refers to a different invoice.

Adjustment amounts must be negative values.

POST https://api.fonoa.com/v1/transactions/adjustment

{
   "country_code": "PT",
   "language_code": "PT",
   "currency_code": "EUR",
   "transaction_date": "2024-03-11T01:00:00+00:00",
   "transaction_id": "Transaction107",
   "items": [
        {
            "type": "GOODS",
            "description": "Product B",
            "code": "SKU3",
            "ean": "2",
            "number": 1,
            "unit": "pcs",
            "name": "Delivery fee",
            "quantity": 1,
            "unit_price": -1000,
            "reference_transaction_id": "Reference105",
            "tax_breakdown": [
                {
                    "rate": 23,
                    "amount": -230,
                    "regime": "IVA",
                    "type": "PT"
                }
            ]
        },
        {
            "type": "GOODS",
            "description": "Product B",
            "code": "SKU3",
            "ean": "2",
            "number": 2,
            "unit": "pcs",
            "name": "Delivery fee",
            "quantity": 1,
            "unit_price": -1000,
            "reference_transaction_id": "Reference106",
            "tax_breakdown": [
                {
                    "rate": 23,
                    "amount": -230,
                    "regime": "IVA",
                    "type": "PT"
                }
            ],
        }
   ],
   "customer": {
       "legal_name": "Futuro Digital Lda",
       "address": {
           "country_code": "PT",
           "city": "Lisboa",
           "postal_code": "1000-046",
           "address_line_1": "R. António Pereira Carrilho 29A"
       },
       "tax_information": {
           "tax_number": "574992960"
       },
       "type": "BUSINESS"
   },
   "supplier": {
       "id": "8db9a4a4aaec4c969a402692eb33035c"
   },
   "type": "FULL",
   "total_amount": -2460,
   "total_net_amount": -2000,
   "total_tax_amount": -460
}