KSeF for microbusinesses — deferral until when 2027

The KSeF deferral for the smallest businesses runs until January 1, 2027. We explain the PLN 10,000 limit, what counts toward it, and when you enter the system for good.

How long does the KSeF deferral for microbusinesses last? Short answer

If you’re a small seller, the key date is January 1, 2027. Until that day — or more precisely, until December 31, 2026 — you can still issue invoices outside KSeF, provided that the total value of your sales documented by invoices subject to the KSeF obligation does not exceed PLN 10,000 gross in a given month. As of January 1, 2027, the e-invoicing obligation in the National e-Invoicing System (KSeF) will cover all taxpayers — with no exceptions and no limits.

This is the only deferral for the smallest businesses that’s actually written into the regulations. It doesn’t mean KSeF doesn’t apply to you — it only means you have extra months to keep issuing invoices the old way before the system becomes mandatory for you. Below, I break it down to the essentials: who exactly qualifies for the deferral, how to calculate the PLN 10,000 limit, what happens once you exceed it, and what you need to keep in mind right now, even though you’re still issuing invoices outside the system.

The KSeF 2026–2027 timeline in a single table

Mandatory KSeF is rolling out in stages. The dates below come from the act and the Ministry of Finance’s current schedule (as of July 2026 — it’s worth confirming the deadlines at the source, since a discussion about further changes is ongoing in the background).

If you want broader context on the whole rollout from an online seller’s perspective, I covered it in KSeF 2026 for e-commerce sellers.

Before you calculate the limit — who KSeF actually covers

As a rule, the obligation to issue structured invoices applies to taxpayers whose place of business is in Poland and who issue invoices in domestic B2B transactions. The scope also includes taxpayers exempt from VAT (whether by entity or by subject matter) — staged entry into the system has been provided for them as well. Invoices that remain outside the KSeF issuing obligation include, among others, B2C invoices to consumers and certain special cases. If your sales are mostly individual customers without invoices, KSeF itself will in practice affect you mainly when receiving cost invoices and when issuing occasional invoices to businesses.

Who qualifies for the deferral — the PLN 10,000 limit step by step

The deferral until the end of 2026 doesn’t depend directly on your legal form or on whether you’re a “microbusiness” in the meaning of the Entrepreneurs’ Law. One threshold is decisive: PLN 10,000 gross per month, calculated in a very specific way.

What exactly counts toward the limit

Toward the limit you count only sales documented by invoices that are subject to the KSeF obligation — meaning, in practice, B2B invoices issued to other businesses with a tax ID (NIP). The limit is gross (VAT included) and calculated separately for each calendar month. So it’s not a threshold on your company’s entire turnover, only on the part of your sales that would have to go into KSeF anyway.

Note: interpretations can differ in the details, and the list of exclusions is sometimes refined. If you’re hovering close to the threshold, confirm how a specific sale qualifies with your accountant or at the source on the official KSeF portal.

Note one more nuance: the limit “resets” each month, but only until you exceed it. Calculating it is simple — you add up the gross value of KSeF-covered B2B invoices issued in a given month and compare it against PLN 10,000. As long as you’re below it, you start the next month from zero. The moment you exceed the threshold, that “monthly” logic stops working: from then on you’re in the system for good, which I explain below.

A real-world store example

You run a WooCommerce store and also sell on Allegro. Most orders are individual customers (B2C) — if you don’t issue them invoices, those sales don’t count toward the threshold at all. In March, however, you issued 6 invoices to businesses for a total of PLN 8,400 gross — you’re within the limit, so you can issue them outside KSeF. In April, those same B2B invoices came to PLN 11,200 gross — the threshold is exceeded, and you enter KSeF. More on the consequences in a moment.

Important: you have to receive KSeF invoices already now

The most common misconception goes: “I have a deferral, so KSeF doesn’t apply to me.” But the deferral applies only to issuing invoices — not to receiving them. As of February 1, 2026, KSeF is the mandatory channel for receiving invoices for all taxpayers, including you if you’re using the PLN 10,000 limit.

In practice, this means that when your supplier — a wholesaler, a courier company, a packaging vendor — issues you an invoice in KSeF, it’s delivered the moment it’s assigned a KSeF number, regardless of whether you check the system. That’s why, even while still issuing invoices the old way, you should already today: authenticate your company in KSeF, assign roles and permissions (including to your accountant or accounting office), and regularly check purchase invoices. Otherwise you’ll miss costs, payment deadlines, and the right to deduct VAT in the right period.

How KSeF changes day-to-day invoicing

It’s worth getting familiar now with what a KSeF invoice looks like, because it differs from an ordinary PDF. Instead of an arbitrary template, you issue a structured invoice in a strictly defined format (the FA schema), which the system accepts and assigns a unique KSeF number. A few practical consequences:

• Issue date vs. delivery date. As a rule, an invoice is considered issued on the day it’s sent to KSeF, and delivered to the counterparty the moment it’s assigned a KSeF number. This matters for payment deadlines and bookkeeping.
• No more quick fixes in an editor. You make corrections with a correcting invoice in the system — you can no longer quietly swap out a PDF file.
• Limited structure. The invoice has predefined fields, so extensive descriptions, graphics, or attachments have to be delivered outside the KSeF document itself.
• B2C customers still get an invoice. To a consumer or a business without convenient access to KSeF, you provide a visualization of the invoice (e.g., a PDF with a code that allows verification), since it’s mainly businesses that check the system day to day.

The sooner you run at least a few such invoices in a test environment, the fewer surprises on the day KSeF becomes mandatory for you.

What happens when you exceed PLN 10,000

The threshold is one-way. A single instance of exceeding PLN 10,000 gross in any month of 2026 means that:

• starting with the invoice that breaks the threshold, you issue all subsequent invoices in KSeF;
• entry into the system is permanent — even if your sales drop below PLN 10,000 in the following months, you don’t go back to issuing outside KSeF;
• the obligation stays in force until the (already-approaching) full obligation as of January 1, 2027.

That’s why it’s not worth running your business right up against the limit. If you already regularly issue B2B invoices close to PLN 10,000, it’s more practical to prepare for KSeF right away than to fall into the system mid-season and configure everything in a rush — especially with multichannel sales, where there are often many invoices coming from different sources.

Entering KSeF early and voluntarily — is it worth it?

The deferral is a right, not an obligation — you can enter KSeF voluntarily earlier, even if you’re within the PLN 10,000 limit. For some sellers it’s a sensible move, for others an unnecessary rush. A rundown of the arguments:

A practical rule: if you regularly issue invoices to businesses and you’re close to the threshold, enter early and get it off your plate. If you invoice businesses truly occasionally, feel free to use the deferral — but remember the mandatory receipt of invoices and the fact that on January 1, 2027, you’ll enter the system anyway.

Cash registers and offline mode — extra loopholes until the end of 2026

Besides the PLN 10,000 limit, the act provides two more transitional solutions that can also be used until the end of 2026:

• Cash-register invoices — until December 31, 2026, you can issue invoices using a cash register. As of January 1, 2027, this option disappears.
• Offline24 mode — when a technical failure occurs on your end, you can issue an invoice in offline mode and send it to KSeF no later than the next business day. This is an emergency measure, not a permanent way to “bypass” the system.

Penalties for not using KSeF — how much you’ll really pay from 2027

During the transition period until December 31, 2026, the tax administration is meant to focus on educating businesses rather than on sanctions. Financial penalties don’t start until January 1, 2027. Under the regulations, they can amount to (figures are approximate — confirm against the current wording of the act):

• up to 100% of the VAT amount shown on an invoice issued outside KSeF against the obligation;
• up to 18.7% of the gross amount of the invoice when no VAT is shown on it;
• the minimum penalty per violation is indicated approximately at PLN 1,000.

In other words: throughout 2026 you have a real safety buffer, but from 2027 every invoice issued outside the system against the obligation is a potential financial risk. It’s worth using this time for a calm rollout rather than putting everything off until December.

Will the deferral be extended to 2028?

In 2026, a private members’ bill reached the Sejm to push the KSeF obligation for microbusinesses further out — there are proposals to extend the transition period even to the end of 2027 or 2028. As of today (July 2026), however, this is only a bill. The Ministry of Finance states that it is not working on another postponement of the deadline and sees no justification for one.

Don’t plan your business around unenacted legislation. Until the change takes effect, the binding date remains January 1, 2027. Treat any further deferral as a bonus, not as an assumption.

How to use the time until the end of 2026 — a checklist

1. Authenticate your company in KSeF and set roles and permissions — including for your accountant or accounting office.
2. Enable and regularly check the receipt of purchase invoices in KSeF — this has been in force since February 2026.
3. Calculate your monthly sales from B2B invoices and see how close to the PLN 10,000 threshold you really are.
4. Organize the data needed for structured invoices: counterparties’ NIP numbers, units of measure, rates, and line-item descriptions.
5. Test issuing invoices in KSeF as a dry run, in a test environment, before the obligation takes effect.
6. Check how your store and marketplace integrations pass data to invoices — a consistent order → invoice flow will save a ton of manual work.

For stores selling across many channels, it’s especially important that order data flows into invoices without manual re-entry. I described how to set this up for selling on Allegro in KSeF and selling on Allegro, and I gathered the general approach to structured invoices on the KSeF invoices page. Multichannel sales management tools — including Nimo, which is currently being built — are ultimately meant to tie this flow together in a single panel, but today the most important thing is to have the KSeF basics ready on your side.

Frequently asked questions

How long exactly does the KSeF deferral for microbusinesses last?

Until December 31, 2026, you can issue invoices outside KSeF if sales from invoices subject to the KSeF obligation don’t exceed PLN 10,000 gross per month. As of January 1, 2027, the obligation covers everyone, with no limit.

Do I calculate the PLN 10,000 limit from my company’s entire turnover?

No. You count only sales documented by invoices subject to the KSeF obligation (in practice, B2B). You don’t count B2C sales without an invoice or transactions outside the scope of KSeF. The limit is gross and calculated separately for each month.

What happens if I exceed PLN 10,000 once?

Starting with the invoice that exceeds the threshold, you issue in KSeF, and entry is permanent — even if sales drop in later months, you don’t go back to issuing outside the system.

Since I have a deferral, can I ignore KSeF until 2027?

No. The deferral applies only to issuing invoices. Receiving invoices in KSeF is mandatory for everyone as of February 1, 2026, so you must have access to the system and be checking purchase invoices already now.

Will the deferral be extended to 2028?

As of July 2026, it’s only a private members’ bill, and the Ministry of Finance does not confirm any work on another postponement. Until any change happens, the binding date remains January 1, 2027.