NAV Online Számla — Hungary's Real-Time Invoice Reporting System

NAV Online Számla (Online Invoice System) is Hungary's real-time invoice reporting system operated by NAV (Nemzeti Adó- és Vámhivatal — the Hungarian Tax and Customs Administration). Unlike clearance systems (KSeF, e-Factura), it is a reporting system: businesses issue invoices in any format and then report the structured data to NAV within 4 minutes. NAV uses the data for real-time VAT matching and fraud detection.

NAV real-time reporting is mandatory since 2021 for all domestic B2B invoices issued by Hungarian VAT-registered businesses, regardless of invoice value. The reporting uses a NAV-specific XML schema (invoiceData.xsd v3.0). Hungary has not yet enacted a full e-invoicing mandate (where structured invoices are sent to buyers), but participates in EU ViDA discussions that may introduce one by 2028.

For B2B invoices, the invoice data must be submitted to NAV within 4 minutes of the invoice being issued (i.e., of the tax point). For B2C invoices, the deadline is 4 days. The 4-minute window is very tight for manual processes — businesses use accounting software or ERP connectors that submit to NAV automatically on invoice creation.

NAV Online Számla v3.0 uses its own XSD schema (invoiceData.xsd), which is not based on PEPPOL UBL or EN 16931. The XML captures invoice header data, line items, VAT breakdown and payment details. The schema is published on the NAV developer portal (onlineszamla.nav.gov.hu). Authentication uses a technical user linked to the company's tax number.

NAV can impose fines of up to 500,000 HUF per invoice for failure to report or late reporting. Repeated violations attract increasing penalties. Because NAV cross-references buyer and seller reports, discrepancies trigger audits. Businesses with large invoice volumes typically invest in automated NAV connectors to stay within the 4-minute window.

No — these are two separate actions. NAV Online Számla is reporting to the tax authority, not invoice delivery to the buyer. The buyer typically still receives the invoice as a PDF by email or through an invoicing platform. Hungary is discussing moving to a full e-invoicing model (where structured invoices are sent to buyers, not just reported to NAV), but as of 2026 that transition has not been mandated.