Extra Fields : Extend Content (Line)

Orderline (Line level - Income)

Include in section "Custom Fields" in the Orderline part.

Key (Line)	Linked Info When Peppol	Description
PeppolUnitCode	Link .	Unit of Measure. Code list. Sample value H87
InvoiceLine.InvoicePeriod.StartDate	Link	Start date of the services (Line level)
InvoiceLine.InvoicePeriod.EndDate	Link	End date of the services (Line level)
PeppolLineID	Link	The line number is autogenerated by Billit. With PeppolLineID, you can set your own value.
InvoiceLine.Note	Link	Extra free text for additional info on line. You can put multiple information elements in one Note segment.
InvoiceLine.OrderLineReference.LineID	OrderLineRef	Link to the line of the order of the buyer.

Examples with Comments on line: (including Delivery Location)

              "CustomFields":
        {
               "InvoiceLine.Note": "LineNote Extra Free text 1234" 
        },

             "CustomFields":
        {
        		"InvoiceLine.Note": "Delivery Location: 752366547
						Extra reference : 138374 "
        },

Orderline (Line level - Income) - Product / Article Information

Key (Line)	Linked Info When Peppol	Description
InvoiceLine.Item.BuyersItemIdentification.ID.Text (*)	Link	ArticleNumber as stored by the buyer of your article
InvoiceLine.Item.StandardItemIdentification.ID.Text (*)	Link	This is the article number according to one of the standardisation types (see next point)
"InvoiceLine.Item.StandardItemIdentification.ID.SchemeID": "0160"	Link	The standardisation scheme ID, example 0160.

Examples Json below:

Standardised article number based on GTIN (GS/1)
Buyersitemidentification:

"CustomFields"  : {
	"InvoiceLine.Item.StandardItemIdentification.ID.Text": "8710400311140",
	"InvoiceLine.Item.StandardItemIdentification.ID.SchemeID": "0160"
    },

"CustomFields"  : {
"InvoiceLine.Item.BuyersItemIdentification.ID.Text": "854565"
    },

If you just want to mention your own article number, then this is done via the API field "Reference", as mentioned in https://docs.billit.be/docs/create-first-invoice.

Orderline (Line level - Income) - Commodity Classification

CommodityClassification:

Allows to include a value linked to a standard/structered ID. This ID gives the meaning.
The ID must be in the list of the allowed values : codelist . Do not use other values ! Each item in the list has a specific signification. If you do not find a value in the list that matches with your content, use another field then Commodity Classification.
Multiple lines with information can be inserted

Key (Line)	Linked Info When Peppol	Description
CommodityClassificationID	Commodity	ID and value of the CommodityClassification.

Popular examples include:

GTIN - Ean number (SRV)
PO number (PO)
Part number (BH)
Batch Number (NB)
Serial Number (SN)

Examples not supported with Commodity Classification : Delivery Location, despatch document reference, weight, Intrastat number.

Example Json below with PO number and GTIN:

"CustomFields"  : {
     "CommodityClassificationPO": "45123456789",
     "CommodityClassificationSRV": "5410355405132"
    },

Orderline (Line level - Income) - AdditionalItemProperty

AdditionalItemProperty:

Allows to include a value linked to a field description (free choice, no code list existing) .
Multiple lines with information can be inserted
When to use ? When there is no structured Peppol field available, and you do not want to use a general field such as Note, then this is the best option.

Key (Line)	Linked Info When Peppol	Description
AdditionalItemPropertyXYZ	AdditionalItemProp	Name and value

Popular examples include

Other product descriptions
Intrastat code
Weight
Dimensions
Any other additional information

Example Json below with Weight and Intrastat code:

"CustomFields" :
{
            "AdditionalItemPropertyWeight": "24 kg",
            "AdditionalItemPropertyIntrastatCode": "4527897"
},

Example Json with Extra / Custom Fields (Income)

See below content of Custom Fields (Income) on Header Level and Detail Line Level.

Example 1 is all main fields, Example 2 is focused on Tax Representative Party.

{
 "OrderType": "Invoice",
 "OrderDirection": "Income",
 "OrderNumber": "QS-002",
 "OrderDate": "2025-05-05",
  "ExpiryDate": "2025-06-30",
  "Reference": "8541518745 ",
  "OrderTitle": "Other Reference 45215487", 
  "Customer": {
   "Name": "Billit",
   "VATNumber": "BE0563846944",
   "PartyType": "Customer",
   "Identifiers": [
        {
        "IdentifierType": "GLN",
        "Identifier": "5430003799999"
        }
    ],
   "Addresses": [
        {
        "AddressType": "InvoiceAddress",
        "Name": "Billit",
        "Street": "Oktrooiplein",
        "StreetNumber": "1",
        "City": "Ghent",
        "Box": "301",
        "CountryCode": "BE"
        },
   ]
   },
 "OrderLines": [
  {
   "Quantity": 1,
   "UnitPriceExcl": 10.0,
   "Description": "Box of cookies",
       "CustomFields"
    :
    {        
               "PeppolUnitCode":"H87", 
               "PeppolLineID": "40",
               "InvoiceLine.Note": "LineNote Extra Free text 1234",
                "InvoiceLine.InvoicePeriod.StartDate":"2025-04-01", 
               "InvoiceLine.InvoicePeriod.EndDate":"2025-04-30"
        },
   "VATPercentage": 6
   },
    {
   "Quantity": 2,
   "UnitPriceExcl": 3.75,
   "Description": "Sticks",
   "VATPercentage": 21
   }
 ]
}

{
 "OrderType": "Invoice",
 "OrderDirection": "Income",
 "OrderNumber": "QS-002",
 "OrderDate": "2025-10-06",
  "ExpiryDate": "2025-11-30",
  "Reference": "8541518799 ", //PO Reference of the buyer
  "OrderTitle": "Other Reference 45215487", // Another reference of the buyer
    "Customer": {
   "Name": "Billit",
   "VATNumber": "BE0563846944",
   "PartyType": "Customer",
   "Identifiers": [
        {
        "IdentifierType": "GLN",
        "Identifier": "5430003799999"
        }
    ],
   "Addresses": [
        {
        "AddressType": "InvoiceAddress",
        "Name": "Billit",
        "Street": "Oktrooiplein",
        "StreetNumber": "1",
        "City": "Ghent",
        "Box": "301",
        "CountryCode": "BE"
        },
   ]
   },
 "OrderLines": [
  {
   "Quantity": 1,
   "UnitPriceExcl": 10.0,
   "Description": "Box of cookies",
       "CustomFields"
    :
    {
               "PeppolUnitCode":"H87", //If you want to set a specific UOM (Unit Of Measure)
               "PeppolLineID": "40",  //Number of the line of the invoice
               "InvoiceLine.Note": "LineNote Extra Free text 1234",  // free text
               "InvoiceLine.InvoicePeriod.StartDate":"2025-04-01", 
               "InvoiceLine.InvoicePeriod.EndDate":"2025-04-30",
               "InvoiceLine.OrderLineReference.LineID": "0010",  //Reference to the Line of the order of the buyer
               "AdditionalItemPropertyWeight": "24 kg",  //AdditionalItemProperty 1
     					 "AdditionalItemPropertyIntrastatCode": "4527897"  //AdditionalItemProperty2
      "InvoiceLine.Item.BuyersItemIdentification.ID.Text": "854565",
 "InvoiceLine.Item.StandardItemIdentification.ID.Text": "8710400311140", // GTIN number
              "InvoiceLine.Item.StandardItemIdentification.ID.SchemeID": "0160" // scheme ID indicating it is a GTIN number
        },
   "VATPercentage": 6
   },
    {
   "Quantity": 2,
   "UnitPriceExcl": 3.75,
   "Description": "Sticks",
   "VATPercentage": 21
   }
 ]
}