Blog
Articles about invoicing and running a small business.
KSeFPolande-invoicingPolish VATNIPKSeF 2.0KSeF token
KSeF 2026 — the complete guide for small businesses in Poland
Poland's national e-invoicing system explained in English. Who it applies to, the deadlines, how to generate a KSeF 2.0 token step by step, and how to send and receive invoices with Invoice.app.
August 23, 20268 min read
KSeFPolande-invoicingKSeF invoiceUPONIP
How to send an invoice to KSeF — step by step
A hands-on walkthrough of sending invoices to KSeF with Invoice.app: connecting with a token, creating the invoice, sending it, checking the status and downloading the UPO.
August 23, 20264 min read
ZUGFeRDXRechnungGermanye-invoicingLeitweg-IDEN 16931
ZUGFeRD & XRechnung 2025 — the e-invoicing guide for small businesses in Germany
Germany's e-invoicing rules explained in English. What ZUGFeRD and XRechnung are, which deadlines apply, and how to create, send and receive e-invoices with Invoice.app.
August 23, 20269 min read