The inFakt Alternative Question: Where Biurko.io Actually Fits

KSeF & e-invoices

Invoicing in Poland, KSeF and the UPO, the ryczałt and the JPK files — written out step by step.

KSeF 2.0 vs 1.0: What Changed in the API and the FA(3) Schema
Invoicing in practice
392

KSeF 2.0 vs 1.0: What Changed in the API and the FA(3) Schema

On 1 February 2026 the FA(3) schema replaced FA(2) and the production 1.0 API stopped working. This was a new integration contract, not an upgrade. Main API changes: JWT authentication decoupled from sessions, mandatory encryption of every invoice, KSeF certificates, per-invoice batch processing, new duplicate detection, new permission model. Main schema changes: an attachment node, a new "Employee" party role, the 0% rate and the NP code split into specific codes, flexible payment terms, IBAN up to 34 characters. The consequences are commercial, not only technical: invoice numbering, VAT rate mapping, and who in your accounting team can actually see a client's invoices.

The PLN 10,000 KSeF Limit in 2027: Will It Stay in Place?
KSeF & e-invoices
439

The PLN 10,000 KSeF Limit in 2027: Will It Stay in Place?

If you run a small business in Poland, you may have heard reassuring news: as long as your invoices stay under PLN 10,000 a month, you can keep issuing them the old way. That is true, but only until 31 December 2026. This limit is not a permanent break. It is a transitional rule built to expire. Why it matters now: from 1 January 2027, the obligation to issue invoices through KSeF (Poland's National e-Invoicing System) applies to everyone, regardless of turnover. Financial penalties start the same day. If you are planning your 2027 operations around this limit, it is worth checking what the law actually says and whether the Ministry of Finance intends to extend anything.

Lost Your Profil Zaufany? How to Recover It and Keep Invoicing in KSeF
KSeF & e-invoices
374

Lost Your Profil Zaufany? How to Recover It and Keep Invoicing in KSeF

You log in to KSeF (Poland's national e-invoicing system) with Profil Zaufany (Poland's free Trusted Profile), and one morning the system tells you it has expired. Since 1 April 2026, issuing invoices through KSeF is mandatory for most businesses, including sole proprietors (KSeF rollout plan, gov.pl), so this is not something to "get to later." Without a valid Profil Zaufany you can't log in through the Węzeł krajowy (the national identity gateway) and you can't generate a KSeF certificate. Invoices pile up, and a client is waiting. The good news: in most cases you recover access in minutes. The catch: if the profile has already expired, the path is different from a simple renewal.

How to Give Your Accountant KSeF Access Without Sharing Your Login
KSeF & e-invoices
398

How to Give Your Accountant KSeF Access Without Sharing Your Login

Here is a habit I keep running into when companies switch to Poland's mandatory e-invoicing: to let the accountant "handle KSeF," someone hands over the login to the owner's Profil Zaufany (Poland's Trusted Profile, the state e-identity used to sign in to public services). Convenient for five minutes, risky for a year. That login is your identity across the whole tax and public administration, not just invoices, and Poland's Ministry of Finance treats sharing it as unacceptable. The good news: you do not need to. KSeF (Poland's National e-Invoicing System) has a built-in permission model. Your accountant gets their own named access and signs in with their own Profil Zaufany, and you can revoke it at any time.

5 KSeF 2.0 Authentication Methods: Which One Is Right for You?
KSeF & e-invoices
400

5 KSeF 2.0 Authentication Methods: Which One Is Right for You?

Before you issue your first invoice through KSeF (Krajowy System e-Faktur, Poland's national e-invoicing system), you have to prove who you are. That sounds trivial, but it's where most people get stuck. KSeF 2.0 offers five different authentication methods, each works differently, and each suits a different type of user. This matters now because KSeF is already mandatory. It applied to the largest taxpayers from 1 February 2026 and to all active VAT payers from 1 April 2026 (ksef.podatki.gov.pl). 2026 was a penalty-free grace period, but from 1 January 2027 the tax office can impose sanctions. Choosing a login method isn't paperwork. It's the precondition for issuing invoices at all.

KSeF 10,000 PLN Limit: Do B2C Sales Count Toward It?
KSeF & e-invoices
418

KSeF 10,000 PLN Limit: Do B2C Sales Count Toward It?

You run a small business in Poland. Some of your sales go to companies, some to ordinary consumers. You have heard about the 10,000 PLN limit that lets the smallest sellers stay outside KSeF (Poland's national e-invoicing system) a little longer. And the obvious question follows: do you add both types of sales together, or only one? This is not a theoretical detail. From 1 April 2026 the obligation to issue invoices through KSeF applies to most VAT payers, but the smallest businesses received a deferral until 31 December 2026, based on this monthly 10,000 PLN limit. From 1 January 2027 the obligation covers everyone. And crossing the threshold even once is irreversible. So it pays to calculate the limit exactly the way the Ministry of Finance calculates it.

KSeF Tokens: How Long Are They Valid, and What Just Changed
KSeF & e-invoices
519

KSeF Tokens: How Long Are They Valid, and What Just Changed

Until spring 2026 the answer was simple. A KSeF token (an authentication key for Poland's national e-invoicing system) worked through 31 December 2026, and from 1 January 2027 only certificates would remain. That certainty no longer holds. On 9 June 2026 Poland's Ministry of Finance (MF) announced that tokens will stay in the system permanently. That changes the practical answer to "how long," but not one detail: it is still a proposal, not a rule. If your accounting software logs into KSeF with a token, you need to know what is already settled and what is not yet in law.

KSeF Login via mObywatel: Can You Log In From Your Phone?
KSeF & e-invoices
397

KSeF Login via mObywatel: Can You Log In From Your Phone?

"Is there a KSeF app for my phone?" is one of the most common questions from business owners since KSeF (Poland's national e-invoicing system) became mandatory. The short answer is a little surprising: yes to the phone, no to issuing invoices from it. Since February 2026, the Ministry has allowed logging in to KSeF with mObywatel, Poland's official government identity app. And because a new wave of companies fell under the obligation in April 2026, far more people now log in manually, which makes the phone question a real one.

KSeF Login in 2026: Trusted Profile, Signature or Certificate
KSeF & e-invoices
461

KSeF Login in 2026: Trusted Profile, Signature or Certificate

The first login to KSeF (Poland's mandatory national e-invoicing system) trips up more people than issuing the actual invoice. The Taxpayer Application shows several authentication methods, and none of them explains which one is right for you. This is not a trivial choice. Since 1 February 2026, KSeF has been mandatory for the largest companies, and since 1 April 2026 for all other businesses (Ministry of Finance timeline). Without valid authentication you can neither issue nor receive a structured invoice.

Can't Log In to KSeF with Profil Zaufany? 7 Reasons and Fixes
KSeF & e-invoices
492

Can't Log In to KSeF with Profil Zaufany? 7 Reasons and Fixes

You enter the company NIP (Polish tax ID), pick Profil Zaufany (Poland's Trusted Profile e-identity), confirm through your bank, and instead of the KSeF dashboard you get an error or bounce back to the start page. Since the launch of KSeF 2.0 (Poland's mandatory national e-invoicing system), this is one of the most reported problems. The good news: it is rarely a fault with your company or a „wrong NIP”. Usually the cause is an expired profile, a data mismatch in the business register, missing permissions for the right entity, or plain browser cache. Each of these has recognisable symptoms and a fix you can apply yourself. Below are the 7 most common reasons Profil Zaufany login to KSeF fails, with concrete steps for each. This matters now, because KSeF is mandatory from 1 February 2026 for the largest companies and from 1 April 2026 for everyone else, and a blocked login means blocked invoicing.

KSeF Tokens Will Not Disappear on 31 December 2026. What Changes
KSeF & e-invoices
479

KSeF Tokens Will Not Disappear on 31 December 2026. What Changes

On 9 June 2026 Poland's Ministry of Finance proposed keeping tokens as a permanent login method for KSeF, including after 31 December 2026. This is a consultation proposal, not law. Even if adopted, tokens get a validity window of 1 to 365 days, and offline invoicing still requires a certificate. The migration is not cancelled. Only its deadline moved.

How to Check If an Invoice Reached KSeF
KSeF & e-invoices
483

How to Check If an Invoice Reached KSeF

You clicked "send," the software showed "sent," and you moved on. The catch: "sent" and "accepted" are two different states. A file can reach the Ministry of Finance gateway and be rejected there, or sit in processing, while you assume the invoice is safely in the system. KSeF (Poland's national e-invoicing system) became mandatory on 1 February 2026 for large taxpayers and 1 April 2026 for everyone else, so this distinction is no longer a technical footnote. An invoice without a KSeF number has not, in formal terms, been issued in the system. Below is how to tell that an invoice truly went through: where to find the KSeF number, what the UPO is, how to read the status, and what to do when the confirmation is missing.

Automatic KSeF Resubmission After an Outage: How Biurko Handles It
Biurko - product
437

Automatic KSeF Resubmission After an Outage: How Biurko Handles It

An invoice issued in offline24 mode must reach KSeF (Poland's mandatory national e-invoicing system) by the end of the next business day. Nobody sends you a reminder. Biurko detects when the KSeF gateway stops responding, issues the invoice in offline mode with the required QR codes, holds it in a queue, and pushes it through the moment the system recovers. No clicking, no duplicates, full audit log.

KSeF Certificate vs Token: Why We Built Biurko on Certificates
Biurko - product
527

KSeF Certificate vs Token: Why We Built Biurko on Certificates

A token carries permissions inside it. A certificate proves identity and nothing else. You cannot issue an offline invoice with a token, and you cannot even request a certificate while authenticated with one. In June 2026 Poland's Ministry of Finance proposed keeping tokens permanently. Our decision has not changed, and here is why.

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