How to Choose Invoicing Software for a JDG Before 2027?
From 1 January 2027, every Polish JDG issuing invoices to businesses must use KSeF, as the PLN 10,000 gross monthly exemption expires. Choosing the right software directly affects whether your documents are accepted by the Ministry of Finance and paired with an official UPO receipt. Review the technical criteria and readiness checklist for sole proprietors.
On 1 January 2027, the last exemption in Poland's e-invoicing rollout ends. Every JDG (sole proprietorship) that invoices other businesses has to issue those invoices in KSeF, Poland's national e-invoicing system run by the Ministry of Finance. That includes the smallest businesses that were allowed to stay outside the system in 2026 as long as their monthly invoiced sales stayed under PLN 10,000 gross.
So the choice of invoicing software for a JDG is now a compliance decision. The software is what gets your invoice into KSeF and brings back the KSeF number. Two months remain.
This guide gives you selection criteria that work for any product, a KSeF checklist to finish before year-end, and an honest look at Biurko, including its free plan. I build Biurko, so I also list what it does not do yet.
What changes on 1 January 2027
KSeF was introduced in stages: from 1 February 2026 for the largest taxpayers and from 1 April 2026 for everyone else. Businesses invoicing up to PLN 10,000 gross a month had until 31 December 2026. The Ministry's KSeF page lists the stages.
The limit is counted per month. If you crossed it during 2026, KSeF became mandatory from the invoice that crossed it. From 1 January 2027, the exemption disappears for everyone.
Penalties are the part most foreign owners ask about. Under the VAT Act as it stands (Article 106ni), financial penalties can be imposed from 1 January 2027, up to 100% of the VAT on the invoice, or up to 18.7% of the gross amount for invoices without VAT. On 20 October 2026, the government sent the Sejm a bill that would move the penalties to 1 January 2028 (summary of the bill). It is still a bill, and it does not change the invoicing obligation itself. You can estimate your exposure with the KSeF penalty calculator.
One more rule to plan for: from 1 January 2027, payments between active VAT payers are expected to carry the KSeF number of the invoice being paid. Your software should surface that number when you pay.
Why not just use the Ministry's free tool?
The Ministry of Finance offers a free KSeF application, and it is enough to issue a compliant invoice. Sending to KSeF is therefore no longer a reason to pay for software. It is the baseline.
The difference shows up after the invoice is issued. VAT registers, the JPK_V7M file, counterparty checks, and shared access for your accountant are outside what the Ministry's tool is designed for. Software earns its fee by taking over that part.
Seven criteria for choosing invoicing software for a JDG
1. Automatic sending at issue. The invoice should go to KSeF the moment you issue it, and the KSeF number should return to the document without manual uploads.
2. Behavior when KSeF is down. The system has outages. Ask how the product handles offline24 mode and failures, whether it re-sends queued invoices by itself, and whether it can avoid sending the same invoice twice. The Ministry's guidance explains the offline modes.
3. The UPO stays with the invoice. UPO (Urzędowe Poświadczenie Odbioru, the official confirmation of receipt) is your proof that KSeF accepted the document. It should be attached to the invoice, not buried in an inbox.
4. Purchase invoices pulled from KSeF. Since 1 February 2026, every business can receive invoices through KSeF. Good software fetches your supplier invoices automatically.
5. Counterparty checks. VAT status, the bank account against the Polish "white list," and EU VAT numbers in VIES, ideally before you save the invoice.
6. A free seat for your accountant. If a Polish bookkeeper handles your filings, they should log in themselves. Check whether that seat costs extra.
7. What you pay after the trial. Find out which plan you land on, and whether invoices or KSeF sending are capped.
If you invoice foreign clients, add an eighth point: bilingual invoices and an NBP exchange rate picked from the dates on the document. Anything else turns into manual work.
Example: a foreign company with a Polish subsidiary
Consider a German consulting firm that employs one Polish contractor through a JDG to serve local clients. The contractor issues six invoices a month, about PLN 18,000 gross, to the German parent and to two Polish customers. That puts the JDG in KSeF already, since the 10,000 limit was passed in 2026.
The German parent needs an English-readable PDF; Polish customers need the KSeF number on the document. The contractor needs both from one invoice: a structured FA(3) file to KSeF and a bilingual PDF to the client. Criteria 1, 3 and the bilingual point decide this case, and the price after the trial matters less.
What Biurko offers, and where it stops
The Free plan at Biurko costs PLN 0 and has no monthly cap on invoices or KSeF sending. You also get VAT registers, a deadline calendar, 1 GB of storage, and 20 AI credits a month for reading purchase invoices from PDFs and photos. It covers 1 company and 1 user. The accountant seat is free and does not count toward the plan limit. The interface is available in English, Polish, and Ukrainian.
New accounts get 14 days of every feature without entering a card, then move to the free plan, not to a paid one. Paid plans start at PLN 29 net a month (Solo: calculated flat-rate tax and a ready JPK file to download) and PLN 59 net (Pro: the declaration is filed with the tax office and the UPO comes back as proof).
The limits, plainly. The full month, from invoice to contributions and filed declaration, currently works for flat-rate taxpayers (ryczałt). On the progressive scale or the 19% flat tax, Biurko handles invoicing, KSeF, and VAT, but the income and expense ledger and advance tax calculations are still on the roadmap. If you use the full ledger (KPiR), the free plan solves KSeF while your accountant keeps the books.
KSeF checklist before 1 January 2027
Confirm your software has an active KSeF connection and an authentication method (token or certificate). Official guidance: podatki.gov.pl/ksef.
Issue a test invoice and confirm it returns with a KSeF number and a UPO.
Turn on automatic sending if available, and check what happens during a KSeF outage.
Check that supplier invoices arrive in your software without manual work.
Agree with your accountant how they get your data: their own login or an export.
Add up your invoices for recent months. If any month passed PLN 10,000 gross, you are already obliged.
Make sure the software shows the KSeF number when you pay a Polish supplier.
Conclusion
The best invoicing software for a JDG in 2027 is not the one with the longest feature list. It is the one that gets invoices into KSeF without your attention, keeps the UPO, and does not surprise you on price. The seven criteria work for any product, including mine.
To test it on your own company, create a Biurko account: 14 days of full features, no card, then a free plan with unlimited KSeF sending.
FAQ
Do I need invoicing software to issue invoices in KSeF? No. The Ministry of Finance provides a free application for issuing KSeF invoices. Software becomes worthwhile when you want automatic sending, the UPO attached to each invoice, VAT registers, and accountant access, which is everything that happens after issuing.
When does KSeF become mandatory for a JDG? For all JDGs invoicing other businesses, it applies from 1 January 2027. If your invoiced sales exceeded PLN 10,000 gross in any month of 2026, the duty started earlier, from the invoice that crossed the limit. See podatki.gov.pl.
Is there free invoicing software with KSeF in Poland? Yes. Beyond the Ministry's own tool, Biurko has a free plan with unlimited invoices and KSeF sending for 1 company and 1 user. Paid plans add tax calculations, JPK files, and filing declarations.
Are KSeF penalties starting in 2027? Under current law, yes, from 1 January 2027. A government bill from 20 October 2026 would postpone them to 1 January 2028, but it is not law yet. The bill does not change the invoicing obligation.
Does a VAT exemption mean I can skip KSeF? No. A VAT-exempt business that invoices other businesses must also use KSeF from 1 January 2027. Invoices to consumers stay outside the system. See the Ministry of Finance.
Legal status as of 30 October 2026. This article is not tax or legal advice; for interpretation questions, check Ministry of Finance sources or ask your accountant.
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