Receive KSeF Purchase Invoices

Context

Your Polish entity will receive supplier invoices via KSeF. They can be viewed in the expenditure section of MyBillit. You can also extract de data and the files via API.
As a receiver, you do not have to send back messages to the sender via KSeF
All relevant data are stored in MyBillit, you can also find them back on the KSeF environment.

How to Get the Information ?

Actions:

What	More Info
Get List of all incoming documents, Use filtering if needed	https://docs.billit.be/docs/get-list-of-incoming-invoices
Get Information about 1 document	https://docs.billit.be/docs/get-information-about-one-invoicecreditnote
Get files	https://docs.billit.be/docs/get-files
Check Status of the Export	https://docs.billit.be/docs/status-of-export
Alternative : Get info without API	https://docs.billit.be/docs/other-methods-of-receiving-invoices

What Files can you extract from Billit via API ?

Type of Information	What	Action API endpoint
PDF file	The PDF coming from KSeF enriched with KSeF signature information	Get v1/files
Messages section	Status info and KSeF XML	Get v1/files
Signature section	KSeF Signature Information including KSeF signature File	Get v1/order

Instruction how to get a File :

Endpoint	Method	Variable
Files : /v1/files/33ae4e0b-a579-46c3-b0d0-839999bb4ac1	GET	Include FileID

Examples of the Json content of the files:

    "OrderPDF": {
        "FileID": "33ae4e0b-a579-46c3-b0d0-839999bb4ac1",
        "FileName": "Invoice_409859_2_CentralneLaboratoriumPomiarowoBa.pdf"
    },

    "Attachments": [
        {
            "FileID": "1d28180f-ed23-4e0d-b2c0-4c4d4af9999e",
            "FileName": "409859_2__23_01_2026 8_50_46.json"
        }
    ],

"Messages": [
        {
            "Description": "9540010231-20260123-010040EC0636-5A",
            "FileID": "6ef998f0-a5ec-425b-bc5f-d99bbd9c99", //File ID of the XML file
            "CreationDate": "2026-01-23T08:51:01.227",
            "TransportType": "KSeF",
            "Success": true,
            "Trials": 2,
            "Destination": "PL6331975945",
            "MessageDirection": "Outgoing"
        }
    ],

"QRCode": "iVBORw0......5ErkJggg==",

Signature Information in the Json body

In the Json a Signature segment is present.


DocumentStamp	KSeF ID
DateTimeInfo	Date of creation at KSeF
QRCode	File with the QR code
StampUrl	Link to KSeF allowing to performn a manual validation

Sample content:

"Signature": {
        "DocumentStamp": "9540010231-20260123-010040EC9999-9A",
        "DateTimeInfo": {
            "DateTime": "2026-01-23T08:52:05.7304125+01:00"
        },
        "QRCode": "iVBORw0KGgoAAAAt2iqF1F..........IaVulUnRe3+iehvq1bqtnaibErkJggg==",
        "StampUrl": "https://qr-test.ksef.mf.gov.pl/client-app/invoice/9540010231/23-01-2026/EpJeQd5vAOUroMnYiN67eI6Z2I8AmOsgIzojUx5t3pc"
    }