KSeF for small businesses: what a sole trader must do
Enter your average business invoice and how many you issue a month. The calculator says whether you stay within the limit and how many invoices remain before the threshold.
Business invoices in a month
PLN 7,380
Within the PLN 10,000 limit: you may issue outside KSeF until 31 December 2026.
| Room left under the limit | PLN 2,620 |
| How many such invoices fit in a month | 4 |
| KSeF mandatory for everyone | 1 January 2027 |
Only invoices that must be issued in KSeF count: not consumer, till or receipt-with-tax-ID invoices (Arts. 145m, 145n; Ministry Q&A 9–12).
Prepared by Radif Partners · Method · VAT Act, regulations and ministry notices checked on 25 October 2026
A small Polish business, including a sole trader and a VAT-exempt taxpayer, has been in KSeF since 1 February 2026 as a recipient: supplier invoices arrive in the system and are downloaded from there. Issuing in KSeF applies from 1 April 2026, with relief until 31 December 2026: if business invoices stay within PLN 10,000 gross a month, they may still be issued as before, on paper or as PDF. Invoices to consumers never have to go to KSeF, and cash-register invoices and receipts with a tax ID up to PLN 450 stay outside the system until the end of 2026. No software purchase is needed to issue: the ministry offers the free KSeF Taxpayer Application in the browser. What you do need is a way to log in and the right permissions, especially for an accountant. With three invoices of PLN 2,460 a month the total is PLN 7,380, so the limit is enough.
Three situations for a small business
| Situation | Receiving in KSeF | Issuing in KSeF |
|---|---|---|
| business invoices up to PLN 10,000 a month | since 1 February 2026 | can wait until 1 January 2027 |
| business invoices above PLN 10,000 | since 1 February 2026 | from 1 April 2026 |
| sales to consumers only | since 1 February 2026 | no obligation |
The limit works under Article 145m of the VAT Act: you add up the gross value of business invoices by month of issue, and once crossed the right to invoice outside the system lapses for good. The ministry explains this in its answers on the limit. Work out your case:
Business invoices in a month
Business invoices in a month
PLN 7,380
| Room left under the limit | PLN 2,620 |
| How many such invoices fit in a month | 4 |
| KSeF mandatory for everyone | 1 January 2027 |
Cash registers and receipts with a tax ID
Until 31 December 2026 invoices issued with a cash register and receipts with a tax ID up to PLN 450 or 100 euros, treated as simplified invoices, may stay outside KSeF. They do not count towards the limit either. From 1 January 2027 an invoice to a business must be issued in the system, even if the till recorded the sale.
How to start at no cost
- Log in to the system with the trusted profile, an e-ID card or a qualified signature; the methods are on the token and permissions page.
- If you use an accountant, grant them permissions, following the ministry page on permissions.
- Practise issuing an invoice in the demo environment or the test environment.
- Download an offline certificate if you want to issue invoices without a connection.
Open a supplier invoice you have downloaded in the FA(3) reader. Which documents go to KSeF at all is covered on the KSeF obligation page, and the scope is also set out on the ministry page.
The most common small-business situations
Services for a few regular clients. A designer or developer with three invoices a month usually stays within the limit, but one larger job is enough to cross it for good. It is better to move to KSeF at once than to watch the total every month. A shop with a till. Until the end of 2026 a till invoice may stay outside the system; from January 2027 an invoice to a business must be issued in KSeF, so the till and the software must work together. Renting premises to a business. A private landlord who is a VAT payer issues invoices to a business tenant in KSeF like any other trader.
If your business is seasonal, remember that the limit is counted separately each month but does not come back once crossed. A busy December can therefore decide that you issue in KSeF in January anyway, although from January 2027 the duty covers everyone in any case.