What is a Faktura?
A faktura (invoice) is a document confirming a sale of goods or provision of services. It is the primary accounting document for both the seller and the buyer, and serves as the basis for settling VAT. The obligation to issue invoices is regulated by the Act of 11 March 2004 on the Tax on Goods and Services.
An invoice fulfills several key functions: it documents a business event, serves as the basis for the buyer to deduct input VAT, constitutes a cost document for income tax purposes (PIT or CIT), and acts as evidence in potential commercial disputes.
Who Must Issue Invoices?
The obligation to issue invoices applies to:
- active VAT taxpayers -- for every sale of goods or services to another business entity,
- VAT-exempt taxpayers -- upon the buyer's request (a so-called VAT-exempt invoice with the "zw" rate),
- entrepreneurs using ryczałt -- an invoice is required regardless of the form of income taxation.
An invoice must be issued no later than the 15th day of the month following the month in which the goods were delivered or the service was performed. Upon the buyer's request, the invoice must be issued by the 15th of the month following the month the request was made (provided the request was made within 3 months of the transaction).
Mandatory Invoice Elements
Under Article 106e of the VAT Act, every invoice must contain:
- Date of issue.
- Sequential number assigned within one or more series, uniquely identifying the invoice.
- Seller and buyer data -- names (or full legal names), addresses, and NIP (tax identification) numbers.
- Date of delivery or service performance (if different from the issue date).
- Description of goods or services -- a precise description of the transaction's subject.
- Unit of measure and quantity of goods delivered or scope of services rendered.
- Net unit price (excluding tax).
- Discount amounts, if applicable.
- Net sales value (excluding tax).
- VAT rate (23%, 8%, 5%, 0%, or exempt).
- VAT amount.
- Gross total (including tax).
Additionally, in specific situations, special annotations are required, such as "cash method," "self-billing," "reverse charge," or "split payment mechanism."
Types of Invoices
Standard VAT Invoice
The most common type of invoice, issued by active VAT taxpayers. It contains all the elements listed above, including VAT rates and amounts.
Proforma Invoice
An informational document issued before the transaction takes place. A proforma is not an accounting document -- it does not serve as a basis for recording revenue or costs and does not entitle the recipient to deduct VAT. It functions as a commercial offer or a basis for advance payment.
Corrective Invoice (Faktura Korygująca)
Issued when data on the original invoice needs to be corrected. Reasons for correction may include: price changes (discounts, complaints), goods returns, errors in buyer data, or mistakes in the VAT rate. A corrective invoice must reference the original invoice (number and date).
Margin Invoice (Faktura Marża)
Used in specific cases where the tax base is the margin (the difference between the selling price and the purchase price) rather than the full transaction value. This applies to tourism services, sales of second-hand goods, works of art, and antiques. The margin invoice does not show the VAT rate or amount.
VAT RR Invoice
Issued by the buyer (not the seller) of agricultural products purchased from a flat-rate farmer. It bears the special designation "Faktura VAT RR" and includes a 7% flat-rate tax refund.
Simplified Invoice
May be issued when the total amount due does not exceed 450 PLN (or 100 EUR). It does not need to contain certain data -- for example, the buyer's full details are not required; the buyer's NIP number is sufficient. A fiscal receipt with the buyer's NIP for amounts up to 450 PLN is treated as a simplified invoice.
Electronic Invoices and KSeF
Electronic invoices (e-invoices) have become increasingly common in recent years. An electronic invoice has the same legal force as a paper one, provided the authenticity of origin, integrity of content, and legibility are ensured.
From 1 February 2026, issuing invoices through the National e-Invoice System (KSeF) becomes mandatory. This system enables the issuance, transmission, and storage of structured electronic invoices in XML format. KSeF will replace previous methods of invoice exchange between business partners and will become the sole source of invoices recognized by tax authorities.
Learn more about KSeF in the article What is KSeF?.
Invoice Issuance Deadlines
| Situation | Deadline | |---|---| | General rule | By the 15th of the month following delivery/service | | Construction services | Within 30 days of service completion | | Delivery of printed books | Within 60 days of goods release | | Upon buyer's request | By the 15th of the month following the request | | Invoice before delivery | No earlier than 60 days before delivery/service |
Invoice Storage
Invoices -- both issued and received -- must be stored for a period of 5 years from the end of the calendar year in which the tax payment deadline fell. In practice, this means retaining documents for 6--7 years from the transaction date.
Invoices may be stored in paper or electronic form. In the case of electronic storage, it must be possible to provide immediate access to invoices and print them upon request by the tax authority.
Invoice data is reported to the tax administration through JPK_VAT files, and from 2026 also via KSeF.
Common Invoice Mistakes
- Missing or incorrect buyer's NIP -- prevents VAT deduction.
- Wrong VAT rate -- may result in tax arrears or the need for correction.
- Missing delivery/service date -- required if it differs from the issue date.
- Imprecise description of goods or services -- makes verification by tax authorities difficult.
- Late issuance -- may result in penalties from the tax office.
If an error is discovered, a corrective invoice must be issued. Detailed instructions on issuing invoices can be found in the guide How to issue an invoice?.
Summary
An invoice is a fundamental document in business transactions -- it confirms the transaction, serves as the basis for tax settlements, and acts as evidence in commercial relationships. Knowledge of mandatory invoice elements, invoice types, and issuance deadlines is essential for every entrepreneur. With the implementation of KSeF in 2026, invoicing is undergoing full digitization, requiring businesses to adapt their processes and tools. If you need support with invoicing and VAT settlements, contact the LinTax accounting firm in Wrocław.