How to declare and tax foreign sales revenue in Poland?

You run a Polish sole proprietorship (JDG) or a Polish subsidiary, and your customer is in Germany, France or the US. The invoice is easy. The questions that follow are not: do you charge Polish VAT, which line of the VAT return does this sale go on, and which exchange rate do you use for income tax?

The stakes are higher in 2026. Poland's national e-invoicing system, KSeF (Krajowy System e-Faktur), became mandatory for most VAT payers on 1 April 2026, and that includes invoices to foreign customers. The penalty-free period for KSeF mistakes ends on 31 December 2026, with sanctions from 1 January 2027.

This guide covers the four types of cross-border sales, VAT, income tax, KSeF and deadlines. I am a software founder, not an accountant, so wherever interpretation matters I point to the law itself.

Step one: classify the sale

Income tax treats all foreign sales alike. VAT does not. Match your transaction to one of four cases:

• Goods to a business in another EU country (WDT, intra-EU supply). 0% Polish VAT if conditions are met. Reported in the VAT return (JPK_V7) and the EC Sales List (VAT-UE); requires EU VAT registration.

• Goods to a customer outside the EU (export). 0% with proof of exit. Reported in JPK_V7; you need proof the goods left the EU.

• Services to a foreign business. Outside the scope of Polish VAT ("NP"). Reported in JPK_V7, and for EU clients also in VAT-UE; the invoice carries a reverse-charge note.

• Goods to EU consumers (distance sales). Above EUR 10,000 you owe the VAT of the consumer's country. Reported in the OSS return (VIU-DO) after OSS registration (VIU-R).

Intra-EU supply of goods (WDT)

A WDT is a shipment of goods from Poland to a VAT-registered business in another EU member state. Under Article 42(1) of the Polish VAT Act, the 0% rate applies only if all of these are true:

1. The buyer gave you a valid EU VAT number (check it in the EU's VIES database).

2. You hold documents proving the goods reached another EU country.

3. You are registered as an EU VAT payer ("VAT-UE") when you report the supply, which means filing form VAT-R before your first such delivery.

Article 42(1a) adds a trap: the EC Sales List (VAT-UE) must be filed on time and be correct, by the 25th day of the month after the tax point. A late or wrong filing can cost you the 0% rate, which is the most common way a legitimate WDT turns into a 23% VAT bill.

Example. You ship goods to a Czech company on 14 October 2026. Both your October VAT return and the VAT-UE are due by 25 November 2026. If you still lack proof of delivery by then, report the sale at the domestic rate and correct it once the documents arrive.

Export of goods outside the EU

Exports (to the US, UK, Ukraine and elsewhere) are taxed at 0% under Article 41(4), provided you hold proof of exit before your VAT return deadline for that period. The standard proof is the electronic customs message CC599C (formerly IE-599).

No CC599C? Not necessarily fatal. The Court of Justice of the EU held in case C-275/18 (Vinš) that what matters is that the goods actually left the EU. Tax offices can still be strict, so keep carrier documents, delivery confirmations and correspondence.

If proof does not arrive by the 25th of the following month, report the sale at the domestic rate (usually 23%) and file a correction for the period in which you receive it.

Services to foreign customers

For B2B services the rule in Article 28b of the VAT Act is simple: the place of supply is where the customer is established, not where you do the work. Because the service is taxed abroad, your invoice carries no Polish VAT. Instead you write "NP" and a reverse-charge note, or cite Article 28b.

In the JPK_V7 file, such services go in field 11. For EU customers, also report them in field 12 and on the EC Sales List. Services to customers outside the EU never go on the VAT-UE.

Watch the exceptions: services connected with real estate or event admission follow their own rules, and services to private individuals are usually taxed in the supplier's country, which means Polish VAT.

Selling to EU consumers: the OSS procedure

If you sell goods online to private individuals in other EU countries, you can apply Polish VAT as long as your total cross-border B2C sales stay below EUR 10,000 (about PLN 42,000) per year, counting the current and previous year together. Above that, you owe VAT at the consumer's local rate. Instead of registering for VAT in every country, you register for the One Stop Shop (OSS) with form VIU-R, by the 10th day of the month after the one in which you crossed the limit, and file a single VIU-DO return. Details are on podatki.gov.pl.

Income tax: PIT on foreign revenue

A Polish tax resident is taxed in Poland on worldwide income (Article 3(1) of the PIT Act). Revenue from foreign customers therefore lands in the same annual return as domestic revenue, under whichever regime you chose: progressive scale, 19% flat tax or lump-sum ("ryczałt"). If you work from Poland and have no branch or fixed place of business abroad, you generally do not pay income tax in the customer's country. If you do have a foreign establishment, check the double tax treaty with that country and talk to an accountant.

Two details cause most errors:

• When revenue arises. For business income, when the amount becomes due (typically the invoice date), not when payment arrives.

• Which exchange rate. For PIT, convert at the NBP average rate from the last business day before the revenue date (Article 11a(1)). VAT uses a parallel rule (Article 31a) pegged to the VAT tax point, so the two rates can differ.

Example. An invoice for EUR 4,500 at an NBP rate of 4.30 (illustrative, not a current rate) gives PLN 19,350 of revenue. If payment later arrives at a different rate, exchange differences may arise (Article 24c of the PIT Act).

KSeF and foreign customers

Invoices for WDT, exports and services to foreign businesses are issued in KSeF just like domestic ones (KSeF 2.0 handbook, section 2.11). A buyer without a Polish tax ID (NIP) cannot log in to KSeF, so you are responsible for delivering the invoice another way, such as a PDF with a QR code by e-mail. Invoices to foreign private individuals stay outside KSeF.

In the FA(3) schema, the rate is tagged like this:

<P_12>0 WDT</P_12>   <!-- intra-EU supply of goods -->
<P_12>0 EX</P_12>    <!-- export of goods -->

For a WDT, the buyer block carries the EU country code and VAT number. A wrong number is the usual reason for a "correct to zero" credit note.

Checklist: foreign sales

1. Classify the transaction: WDT, export, B2B service or B2C sale.

2. Validate the buyer's EU VAT number in VIES before invoicing and keep the result.

3. Confirm you are registered as an EU VAT payer (WDT and EU services).

4. Collect proof of delivery or exit as you go, not after an audit letter.

5. File JPK_V7 and VAT-UE by the 25th of the following month.

6. Convert currency at the correct NBP rate, separately for VAT and PIT.

7. Track total EU B2C sales against the EUR 10,000 threshold.

Conclusion

Foreign sales are manageable once you know which of the four cases you are in. The real risk is not the rate itself but deadlines and paperwork: VAT-UE by the 25th, proof of exit before the return, a valid buyer VAT number.

Biurko issues bilingual invoices, sends them to KSeF at issue, and prepares JPK_V7 with the UPO confirmation. To be straight about limits: Biurko does not file VAT-UE or OSS returns today, so you handle those outside it. If you want to see KSeF invoicing in practice, start a 14-day free trial at biurko.io.

FAQ

Do I report foreign sales in my Polish VAT return? Yes. Even when no Polish VAT is due, intra-EU supplies, exports and services taxed abroad appear in dedicated fields of the JPK_V7 file. Intra-EU supplies and B2B services to EU customers also go on the EC Sales List (VAT-UE) by the 25th of the next month.

Can I zero-rate an EU sale if my customer has no VAT number? No. A valid EU VAT number given by the buyer is a condition of the 0% rate. Without it, treat the sale as domestic and charge Polish VAT. Check the number in VIES before invoicing and save the confirmation.

Which exchange rate do I use for a EUR invoice? For VAT, the NBP average rate from the last business day before the tax point (Article 31a). For income tax, the NBP rate from the last business day before the revenue date (Article 11a). The dates can differ, so the rates can too.

When did KSeF become mandatory for export and intra-EU invoices? On 1 April 2026 for most VAT payers, and on 1 February 2026 for companies with 2024 sales above PLN 200 million. Foreign customers without a Polish tax ID receive the invoice outside the system, for example as a PDF.

What is the EU distance-selling threshold? EUR 10,000 (about PLN 42,000) in total across all EU countries, measured over the current and previous calendar year. Above it, you owe VAT at the consumer's local rate, which you can report through the OSS procedure.

This article is informational and is not tax or legal advice. For unusual transactions, consult an accountant or tax adviser.

Sources: VAT Act (ISAP), PIT Act (ISAP), OSS registration, podatki.gov.pl, KSeF 2.0 handbook, CJEU C-275/18.