Billit vs phase4

Billit is an invoicing and administration platform for businesses to create and send invoices, track payments, and share documents with an accountant. For Peppol e-invoicing, it converts invoices into the required format and sends them over the Peppol network. Its app scans VAT receipts, and the service recognizes relevant information and amounts from submitted documents. Billit can send automatic reminders for overdue invoices and connects with banks, accounting packages, online shops, cash register systems, and business software. An open API supports custom integrations. The platform is available on Android, iOS, and web, with API access and cloud deployment. A free license covers Peppol sales invoices only and has limited functionality. Paid plans start at €6.90/mo (annual), and a 15-day trial is listed. Monthly document allowances vary by plan; invoices, credit notes, and receipts count toward the allowance, and extra usage is billed when it is exceeded.

phase4 is a free, open-source Java library for sending and receiving AS4 messages. It is designed for manual integration into an existing system, not as a standalone project. Built-in protocol support includes Peppol and CEF eDelivery; documented additional profiles include BDEW, DBNAlliance, eDelivery2, EESPA, ENTSOG, EUCTP, and HR eDelivery. The library supports UBL and API access, and is intended for on-premise deployment. It requires Java 17 or later, with Java 21 or later recommended for performance. Configuration can come from application.properties, system properties, or environment variables; security setup can use JKS or PKCS12 keystores and truststores. AS4 multi-hop and AS4 split and join are not implemented. The project says automated unit and integration tests cover many configurations, while testing against a real remote system is different. Its testing guide says an official Peppol AP certificate is needed to test sending to or receiving from an existing Peppol provider. phase4 uses the Apache 2.0 license.