einvoice-preflight now has Latvia and Slovenia pages, the 24th and 25th in its country set.
Latvia has required e-invoices for sales to state budget bodies since 1 January 2025. The business-to-business duty was due on 1 January 2026; per vendor guides the Saeima moved it to 1 January 2028 on 5 June 2025. One guide still prints 2027, which looks stale, and the page says so.
Slovenia adopted its law on 23 October 2025 for 1 January 2028, after mid-2026 and 2027 targets slipped. Guides say a PDF will not count, accepted formats are the national e-SLOG and EN 16931, and the final text dropped the e-reporting duty. One source gives fines; only one source does, so the page leaves them out.
Both pages rest on vendor and advisory sources found by web search. The Latvian Law on Accounting, the State Revenue Service and Slovenia's Financial Administration were not read, and each page tells the reader to confirm there. The checker covers EN 16931 and Peppol BIS 3.0, not e-SLOG or the Latvian reporting, and the pages state that limit.