Poland: October 2026 tax and social security changes for entrepreneurs

Poland introduces mandatory e-Deliveries for entrepreneurs from October 1, with potential penalties for non-compliance. The EU is revising social security coordination rules, complicating employer seat determination. ZUS contribution refunds and tax ordinance amendments bring changes to tax treatment, while a CJEU ruling affects compensation for overdue invoices. These administrative and regulatory shifts alter compliance burdens and financial planning for Polish businesses.