Knowledge Base
    e-invoicing

    CSID (Cryptographic Stamp Identifier)

    A digital certificate issued by ZATCA to a Saudi VAT-registered seller, used to cryptographically sign each Phase 2 e-invoice (XAdES over UBL 2.1) before it is cleared or reported through the Fatoorah portal.

    More Details

    The CSID is provisioned through an in-system CSR + OTP flow with the ZATCA Fatoorah portal. The private key never leaves the seller's e-invoicing system; the signature it produces binds the invoice hash chain, seller VAT number, and UUID, making any post-issue edit detectable. Each seller may hold multiple CSIDs (one per device or business unit).

    Related Terms

    XAdES (XML Advanced Electronic Signatures)UBL 2.1 (Universal Business Language)QR-coded Tax Invoice

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