Businesses increasingly use electronic ways of sending accounting documents. Sending invoices electronically has become particularly popular, both as PDF files sent by email and as traditional faxes. For active VAT taxpayers the key question is whether these ways of receiving invoices comply with the law and whether they allow an effective deduction of input VAT. From 2026 the answer depends above all on KSeF (National e-Invoicing System): as a rule, invoices are issued in this system, and a PDF or fax is allowed only in exceptional cases.
The issue is becoming more important as business processes are digitised and companies try to cut the cost and time of handling paperwork. At the same time, taxpayers must comply with the strict requirements of the VAT Act, which govern issuing, receiving and storing invoices.
An active VAT taxpayer who wants to exercise the right to deduct VAT must hold an invoice issued by the seller in line with the requirements of the VAT Act. The way the invoice is received matters for whether it can be used in tax settlements
Types of invoices under the VAT Act
The VAT Act defines an invoice precisely and sets out the different forms it can take. Under Article 106b(1) of the VAT Act, a taxpayer making a sale to another taxpayer must issue an invoice. This applies both to supplies of goods for consideration and to services provided for consideration.
The legal definition of an invoice in Article 2 point 31 of the VAT Act is crucial. Under this provision, an invoice is a document in paper or electronic form containing the data required by the Act and by the regulations issued under it. The definition clearly shows that the legislator allows two basic forms of invoices: paper and electronic. The Act also distinguishes the structured invoice – issued in KSeF together with the number assigned to it in that system (Article 2 point 32a) – and from 1 February 2026 taxpayers are, as a rule, obliged to issue precisely such invoices (Article 106ga(1)). What an exempt seller's invoice must show is described in our post on the legal basis for VAT exemption on invoices.
Article 2 point 32 of the VAT Act defines an electronic invoice as an invoice in electronic form issued and received in any electronic format. The key point is that an electronic invoice has no paper form from the very start
Pay particular attention to the change in the rules on electronic invoices. Until 31 January 2026 Article 106n of the VAT Act required the recipient to accept an electronic invoice. From 1 February 2026 this provision is repealed: electronic invoices issued outside KSeF are sent or made available by the seller to the buyer in a manner agreed with the buyer (Article 106gc(1) of the VAT Act), and the buyer receives structured invoices in KSeF without separate consent (Article 106gb(1)). Since invoices reach KSeF without the buyer's consent, it is worth knowing the rules of due diligence with invoices from fraudsters.
The rules also allow more than one electronic invoice to be sent or made available to the same recipient at the same time. In that case data common to the individual invoices may be given only once, provided that all the required data are available for each invoice (Article 106gc(4)).
PDF invoices sent by email
Sending invoices as PDF files to the buyer's email address has become very popular among businesses. It combines the convenience of electronic delivery with a document that is easy to read. From 2026, however, it is allowed only where the taxpayer does not have to issue the invoice in KSeF – among others for sales to consumers, for taxpayers with no registered office or fixed establishment in Poland and for those using the exemption under Article 113a (Article 106ga(2)–(3)), and until 31 December 2026 also for sales documented by such invoices of up to PLN 10,000 gross per month (Article 145m) and for invoices issued from a cash register (kasa fiskalna) (Article 145n). A PDF sent for an invoice issued in KSeF is only a preview of it – the invoice is the document in KSeF. The Director of National Tax Information confirmed that this solution is acceptable in an individual tax ruling (KIS) of 11 September 2019 (No 0113-KDIPT1-3.4012.432.2019.1.ALN), issued before mandatory KSeF was introduced.
The ruling stated that a buyer who accepts the terms and conditions of a mobile app consents to receiving invoices as a PDF file sent to the email address given at registration. Therefore, sending a PDF invoice to the email address indicated by the buyer, at the buyer's request, means that the document has been made available to the buyer.
An invoice issued in PDF format and sent by email is an electronic invoice within the meaning of the VAT Act. Until 31 January 2026 it required the recipient's acceptance (Article 106n, now repealed); from 1 February 2026 it may be issued only under the exceptions to the KSeF obligation, and it is sent in a manner agreed with the buyer (Article 106gc(1))
Invoices sent by fax
Invoices sent by fax are treated differently. An invoice sent by fax is not an electronic invoice within the meaning of the VAT Act. The point made is that an electronic invoice has no paper form from the very start. If a paper invoice is issued and then sent by fax, the use of a fax alone does not turn it into an electronic invoice.
As a result, Article 106n of the VAT Act, which until 31 January 2026 required recipient acceptance only for electronic invoices, did not apply to an invoice sent by fax. An invoice sent by fax remains a paper invoice, even though it was transmitted electronically – and from 2026 a paper invoice, like a PDF, is allowed only under the exceptions to the obligation to issue invoices in KSeF (Article 106ga(2)–(3), Articles 145l–145n).
An invoice sent by fax is treated as a paper invoice, so it did not require the recipient acceptance that electronic invoices required until 31 January 2026. The tax effects of issuing both types of invoice are, however, identical
Legal basis for deducting VAT
The right to deduct VAT is regulated in detail in the VAT Act. Under Article 86(1) of the VAT Act, to the extent that goods and services are used to carry out taxable activities, the taxpayer has the right to reduce output VAT by input VAT.
Article 86(2) point 1(a) of the VAT Act is crucial: it states that input VAT is the sum of the tax amounts shown in invoices received by the taxpayer for purchases of goods and services. This provision clearly points to the invoice as the basic document giving the right to deduct VAT.
The moment the right to deduct arises is set out in Article 86(10) of the VAT Act. Under this provision, the right to reduce output VAT arises in the settlement for the period in which the tax point arose in respect of the goods and services purchased by the taxpayer. We prepare VAT settlements and JPK files for clients of our accounting firm in Warsaw.
The right to reduce output VAT by input VAT arises no earlier than in the settlement for the period in which the taxpayer received the invoice or customs document, in line with Article 86(10b) point 1 of the VAT Act. A structured invoice is deemed received on the day its number is assigned in KSeF (Article 106na(3))
Conditions for an effective VAT deduction
For the right to deduct VAT to be exercised effectively, certain legal conditions must be met. The basic requirement is that the taxpayer holds an invoice or customs document. If the taxpayer does not have the invoice when the tax point arises, the right to deduct moves to the moment the invoice is received.
Importantly, the rules do not make the right to deduct depend on whether the taxpayer holds an electronic or a paper invoice. This means that the form of the invoice – traditional paper, electronic PDF or sent by fax – does not affect the possibility of deducting VAT. This also applies to structured invoices received in KSeF.
However, the taxpayer must make sure the invoice contains all the elements required by Article 106e of the VAT Act and that the deadlines for issuing invoices under Article 106i of the VAT Act are met.
- Check that the invoice data are complete under Article 106e of the VAT Act
- Make sure the invoice documents a real business transaction
- Check whether the goods or services will be used for taxable activities
- Keep the invoice in a form that allows it to be presented to the tax authorities later
- Enter the invoice in the VAT records in the correct settlement period
Requirements for the authenticity and integrity of invoices
The VAT Act requires the authenticity of origin, integrity of content and legibility of an invoice to be ensured. These requirements are set out in detail in Article 106m of the VAT Act: for structured invoices they are ensured by KSeF (section 1), and for other invoices – including PDF and paper ones – the taxpayer decides how to ensure them (section 1a). They are crucial for an effective VAT deduction.
Authenticity of origin means certainty as to the identity of the supplier of goods or services or of the issuer of the invoice. This is a basic element of verification, intended to ensure that the invoice really comes from the entity that made the sale.
Integrity of content means that the data an invoice should contain under the VAT Act have not been changed. This requirement is intended to ensure that the document has not been modified after the seller issued it.
The authenticity of origin, integrity of content and legibility of an invoice other than a structured one can be ensured by any business controls that create a reliable audit trail between the invoice and the supply of goods or services
Business controls and the audit trail
Business controls should be appropriate to the size, activity and type of taxpayer. They must take into account the number and value of transactions, as well as the number and type of suppliers and buyers. Where relevant, other factors affecting the nature of the taxpayer's business should also be considered.
An example of a business control is holding supporting documents, such as:
- Orders confirming the intention to make the transaction
- Contracts setting out the terms of cooperation
- Transport documents confirming delivery of the goods
- Payment reminders and payment confirmations
- Business correspondence connected with the transaction
A reliable audit trail means that the link between the supporting documents and the transactions carried out is easy to follow, because there are enough data to connect the documents
The audit trail must follow the procedures set in the business and reflect the processes that actually took place. For VAT purposes it should provide a verifiable link between the invoice and the supply of goods or services, so that it can be checked whether the invoice reflects a real transaction.
Practical aspects of receiving invoices electronically
Businesses that receive invoices electronically must pay attention to several important practical aspects. First of all, until 31 January 2026 consent to receive electronic invoices was required; from 1 February 2026 electronic invoices issued outside KSeF are sent in a manner agreed with the buyer (Article 106gc(1)). This arrangement can be made in various ways, including by accepting terms and conditions, signing a contract or making a statement.
In practice, buyers often consent to receiving electronic invoices when they register in the supplier's system or sign a contract. This documents the agreed method of sending invoices required by Article 106gc(1) of the VAT Act.
In 2025 an accounting services firm signed a contract with a software supplier in which it agreed to receive invoices as PDF files sent to a designated email address. All invoices received in this way could be used to deduct VAT, provided they contained all the elements required by law and documented real transactions. From 2026 such a supplier, as a rule, issues invoices in KSeF and the firm receives them there – a PDF sent by email is then only a preview of the invoice.
| Form of invoice | Recipient acceptance (from 1.02.2026) | Legal basis | VAT deduction possible |
|---|---|---|---|
| Paper invoice | No | Article 2 point 31 and Article 106gc(5) of the VAT Act | Yes |
| Electronic PDF invoice | No – method of sending agreed with the buyer | Article 106gc(1) of the VAT Act (until 31.01.2026 Article 106n) | Yes |
| Invoice sent by fax | No | Article 2 point 31 of the VAT Act | Yes |
| Invoice in an EDI system | No – conditions set by the EDI agreement | Article 106m(5) point 2 of the VAT Act | Yes |
Archiving and storing electronic invoices
Taxpayers who receive invoices electronically must store them properly for the period required by law. Electronic invoices can be stored electronically, but they must be protected against loss, destruction or unauthorised access.
It is essential to keep invoices legible throughout the storage period. This means the taxpayer must have suitable software and hardware to read the invoices in the future, even if technology changes.
Electronic invoices must be stored in a way that ensures their legibility, integrity and availability for the entire period required by law. The taxpayer is responsible for choosing suitable archiving methods
Procedures for checking invoices received electronically
Receiving invoices electronically requires taxpayers to put suitable verification procedures in place. Their purpose is to make sure that the documents received really come from the stated issuers and have not been modified in transit.
The basic element of verification is checking whether the invoice contains all the elements required by law. This applies in particular to the data identifying the seller and buyer, the description of the transaction, the net and gross amounts and the VAT rates.
It is just as important to check that the invoice data match the actual transaction. The taxpayer should compare the information on the invoice with supporting documents such as orders, contracts or transport documents.
- Check the seller's identification data, including the NIP (tax identification number)
- Check that the description of the goods or services matches the actual transaction
- Check the amounts and VAT rates
- Compare the invoice data with supporting documents
- Check whether the seller is a registered VAT taxpayer
What to do if in doubt
If a taxpayer has doubts about the authenticity of an invoice received, they should take additional verification steps. These may include contacting the seller directly to confirm that the invoice was issued, checking the seller's data in public registers or asking for additional documents confirming the transaction.
If it turns out that the invoice may not be authentic or may contain incorrect data, the taxpayer should hold off deducting VAT until the doubts are cleared up. Deducting VAT on the basis of an invoice about which the taxpayer has reasonable doubts may lead to negative tax consequences.
The taxpayer must exercise due diligence when checking invoices received. If there are doubts about an invoice's authenticity, additional verification steps should be taken before deducting VAT
Legal consequences of an incorrect VAT deduction
Deducting VAT on the basis of incorrect invoices may have serious legal and financial consequences. The tax authorities may challenge the right to deduct, which means paying the tax due together with interest.
If it is found that the taxpayer deducted VAT on the basis of invoices documenting non-existent transactions or invoices containing false data, the authority may set an additional tax liability (the so-called VAT sanction). As a rule, it is up to 30% of the amount by which the tax liability was understated (Article 112b of the VAT Act), and where the deduction results from an invoice issued by a non-existent entity or stating activities that were not carried out, and was the result of deliberate action by the taxpayer or by a counterparty the taxpayer knew about – 100% (Article 112c).
Particularly severe consequences apply to participation in carousel fraud or other schemes aimed at extorting VAT. In such situations criminal proceedings may be brought in addition to tax penalties.
A business received electronic invoices from a supplier that turned out to be unreliable. Although the invoices formally contained all the required elements, they documented non-existent transactions. As a result of a tax audit, the business had to correct the deduction and pay the tax arrears with late-payment interest, and the authority set an additional tax liability of 30% of the understated amount (had it been shown that the business knew the transactions were fictitious – 100%).
