In European Countries implementation of electronic invoices become wider gradually. For instance Serbia implementation process completed with B2B transactions in January 2023.
France, Spain, Slovakia and Poland e-Invoice system is expected to be mandated in 2024. Each country has their own timeline, scope, obliged taxpayers and technical details.
At the end of the 2022 EU commision approved the postponement of the Polish e-Invoice system April 2023 to January 2024. With the latest update obligation date can be postponed additional 6 months and can begin in July 2024. It is still in proposal status. Advantages of voluntary process still continue and penalties will be applied in case of non-compliance with e-Invoice rules after January 2025.
You can reach the official announcement here.