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KSeF from 1 January for small businesses

From 1 January 2027 every business issues its invoices in KSeF, including the smallest ones that could still stay outside it until the end of 2026. You can get ready in one afternoon, for free.

What changes on 1 January 2027

  • You issue your sales invoices in KSeF. This includes businesses with sales up to PLN 10,000 a month.
  • Mistakes in KSeF can be fined.
  • When you pay another business by bank transfer for a KSeF invoice, you put its KSeF number in the transfer title.
  • Your suppliers already send invoices to KSeF, so you can see them right away.

Get ready in 3 steps

  1. Create a free Księguś account. No card needed. For 30 days you have the full PRO plan, then you stay on the free Start plan.
  2. Connect Księguś to KSeF. Generate a token in the KSeF taxpayer app and paste it into Księguś. See how.
  3. Issue your first invoice in December. You will know everything works before KSeF becomes compulsory.

Create a free account

What you get free in the Start plan

  • Up to 10 sales invoices sent to KSeF a month. Correction invoices do not count.
  • Supplier invoices from KSeF, without limit.
  • A counter that shows how many free invoices are left this month.
  • An account for your accountant, also free.

Issue more than 10 invoices? The Invoices plan, without limit, costs PLN 35 net a month. See pricing.