Knowledge Base
How invoicing works in Poland — the rules, the edge cases, and Biurko itself.
Browse by Category
Explore our documentation organized by topic
Getting Started
First steps with Biurko platform
2 articles
KSeF Integration
How KSeF works, statuses, environments, and troubleshooting
5 articles
Invoicing
Invoice workflow, statuses, and transmission process
3 articles
Invoicing in Poland
Polish invoicing rules, VAT rates, deadlines, and legal requirements
8 articles
AI & Automation
Connect AI assistants to your company over the MCP protocol
1 articles
Getting Started
First steps with Biurko platform
KSeF Integration
How KSeF works, statuses, environments, and troubleshooting
What is KSeF?
Introduction to the Polish National e-Invoice System
KSeF Statuses
Understanding invoice statuses in KSeF
KSeF Certificates
How to manage certificates for KSeF authentication
Sending Invoices to KSeF
How to submit invoices to the National e-Invoice System
KSeF Environments
Production, Test, and Demo environments explained
Invoicing
Invoice workflow, statuses, and transmission process
Invoicing in Poland
Polish invoicing rules, VAT rates, deadlines, and legal requirements
Types of Invoices
VAT invoice, proforma, advance payment, corrective, margin and simplified invoices
Required Invoice Elements
Mandatory fields on a Polish VAT invoice per Article 106e of the VAT Act
VAT Rates in Poland
Standard, reduced, zero rates and VAT exemptions explained
Invoice Deadlines
When to issue invoices — the 15th-day rule, exceptions, and consequences
Corrective Invoices
When and how to issue correction invoices and correction notes
Split Payment (MPP)
When split payment is mandatory and how it works
Foreign Currency Invoices
Currency conversion rules, NBP exchange rates, and EUR invoicing
Archiving Requirements
Storage periods, digital archiving rules, and KSeF as an archive
AI & Automation
Connect AI assistants to your company over the MCP protocol