How to choose KSeF software for your company?

I am the founder of Biurko, so discount this accordingly. I would still rather lose you at signup than three months in, when you discover we do not do the one thing you needed.

The mandate is already live: 1 February 2026 for the largest taxpayers and 1 April 2026 for all remaining VAT payers; the smallest follow from 1 January 2027. Until 31 December 2026, taxpayers whose monthly gross value of B2B invoices covered by the KSeF obligation does not exceed PLN 10,000 may issue invoices outside KSeF. Invoices to consumers, receipts with a NIP, simplified invoices up to PLN 450 and till sales do not count toward the limit. Crossing the limit is irreversible: from the invoice that exceeded it, you issue in KSeF. Under the current act, penalties under Article 106ni of the VAT Act apply from 1 January 2027. On 16 September 2026 the Ministry of Finance announced it will move them to 1 January 2028; that is a bill not yet passed, and it moves only the penalties, not the obligation to use KSeF. If you are choosing a tool now, you have time to test it calmly.

What Biurko does not do

Starting with the gaps, because these are what usually rule us out.

• No payroll or HR module. No payslips, no ZUS (social insurance) filings for employees, no leave tracking.

• No inventory or retail. No stock levels, no fiscal printer support, no online cash registers.

• No e-commerce integrations. No native connectors for Allegro, Shoper, WooCommerce or BaseLinker.

• No full statutory accounting for companies. Ledgers, balance sheet and annual financial statements are out of scope. We keep the revenue ledger for lump-sum taxpayers; there is no KPiR (the simplified revenue and expense ledger) and no annual PIT return.

• No accountant included. Biurko is software, not an accounting practice. Nobody here will tell you whether an expense is deductible.

• Limited cost automation. AI reads purchase invoices from a PDF or a scan (1 AI credit per page, up to 30 pages; the FREE plan has 20 credits a month), but you choose the cost category yourself: there is no automatic categorisation.

• We are a small, young team. inFakt and iFirma have been around for over a decade. That is a real risk to weigh.

When a competitor is the better choice

You need an accountant, not software

If your problem is not "how do I issue this invoice" but "can I deduct this", another dashboard will not help. inFakt and iFirma sell bookkeeping as a service: you get an app plus an assigned accountant who handles PIT, VAT and ZUS. You pay several hundred zloty a month instead of a few dozen, and what you buy is accountability rather than an interface.

The same logic applies to a local accounting office. If your bookkeeper already works well in a specific system, changing tools on your side only makes their job harder.

You sell physical goods

A retail location, marketplace sales, shipping, stock levels: that is a different class of problem from B2B invoicing. Systems with inventory and integrations win here: iFirma (known for fiscal printer and marketplace integrations), wFirma, and at larger scale Subiekt nexo or Comarch ERP Optima.

A concrete case: a cosmetics seller on three marketplaces issues around 900 documents a month, of which most are receipts and receipt-linked invoices generated automatically from orders. Biurko would handle the KSeF submission, but it would not remove a minute of the order-processing work. The right answer for them is an e-commerce system with a KSeF module.

You run a Polish limited company on full books

A sp. z o.o. on statutory books needs a chart of accounts, a balance sheet, a profit and loss statement and an XML financial statement for the court register. wFirma offers self-service full accounting; inFakt and iFirma handle companies through an assigned accountant. Biurko does not do this and will not this year.

Your ERP already runs your operations

If orders, production and stock have lived in Comarch or Subiekt for five years, moving only the invoicing into a separate tool is the worst available move. You split your source of truth in two and start reconciling registers by hand. Buy the KSeF module from your existing vendor, even if it is clunkier than ours. Data consistency beats a nicer screen.

You employ people

One employment contract is enough for Biurko to stop being sufficient. You need a system with an HR module, or an accounting firm that runs payroll.

When Biurko is the better choice

KSeF is your actual problem

Most products on the market are accounting or invoicing systems with KSeF bolted on during 2025 and 2026. Biurko was designed around KSeF from the first commit. In practice that means:

• Profil Zaufany or KSeF certificate authentication (your own or one ordered through Biurko) rather than tokens, which matters when several people work under one NIP (tax identification number),

• KSeF error messages translated into plain language instead of a raw API code,

• offline24 and emergency mode support, with the KOD I QR code on the PDF (and KOD II when the company holds a KSeF certificate of the Offline type),

• FA(3) and FA_RR schemas (FA_RR is the flat-rate farmer invoice), which most lightweight invoicing tools skip,

• purchase invoice import from KSeF (manual, or on a schedule you switch on in company settings). Documents are flagged for review when the data needs a human, for example a correction whose original is not in your account.

You run an accounting practice

This is where the access model differs most. Biurko has no separate workspace for accounting practices: the accountant joins a client's company as a free guest (one seat in every company, on every plan, including the free one) and switches between companies in one click. You choose the plan for each company separately:

Annual billing carries a 20 percent discount. Every new company gets 14 days of the TEAM plan without a card, then moves to the free FREE plan. TEAM at PLN 99 net per month gives five users and lets you run up to five companies, each company having its own plan. SCALE at PLN 199 net removes both limits, and you set roles and permissions per user. With many clients, add up the plan of each company separately.

Your team works in Ukrainian

Biurko ships a full Ukrainian interface, not a partially translated menu. If your Polish entity is run day to day by someone whose Polish is a second language, that measurably reduces data entry errors.

You want to automate

Biurko exposes an MCP (Model Context Protocol) server endpoint (from the SOLO plan), so an AI assistant (for example Claude, ChatGPT or Cursor) can issue invoices, check submission status or pull counterparty data from the GUS business register. If you are thinking about driving invoicing through an AI assistant, this is something classic systems do not offer.

Price is not the same as cost

When you compare offers, check three things the pricing page usually hides:

1. What the charge is based on: per company, per user, per document, or per module.

2. What costs extra: inventory, payroll, additional users and integrations are often billed separately.

3. What exit looks like: can you export counterparties, products and invoices to CSV or XLSX, or are you left with PDFs?

The third point matters most and gets checked least. Software you cannot leave costs more than its price list says.

How to test any of this in 30 minutes

Instead of reading comparisons, including this one, run a test on the Biurko demo (demo.biurko.io, 7-day access, the KSeF demo environment). An account on app.biurko.io sends invoices to production KSeF, so every invoice you send there is real. This order surfaces the most problems:

1. Issue a VAT invoice with two lines at different VAT rates.

2. Submit it to the KSeF demo environment and download the UPO (official receipt confirmation).

3. Issue a correction to that invoice and check whether the system links it to the original correctly.

4. Import purchase invoices from KSeF and count how many fields you still fill in by hand.

5. Export everything to CSV and open the file.

6. Trigger an error on purpose, for instance with an invalid buyer NIP, and see what the system tells you.

Step six reveals more about a tool than its entire features page.

Selection checklist

• Write down your real monthly volume: invoices, corrections, purchases, entities, users.

• Mark what you need beyond invoicing: inventory, payroll, full accounting, e-commerce.

• If you marked any of those, Biurko is not for you and a trial is not worth your time.

• Decide whether you are buying software or an accountant. They are different purchases.

• Test KSeF submission and UPO retrieval on a demo environment before you pay anything.

• Verify data export before your first payment, not a year later.

• Calculate annual cost at your entity and user count, not the headline entry price.

Summary

The right tool is the one that fits your process, not the one with the longest feature list. If you move goods, employ people or run statutory books, choose a system with inventory, payroll and full accounting. If your real problem is KSeF submissions, corrections, purchase imports and juggling several entities in one place, that is exactly what we built Biurko for.

Create a free account at biurko.io and judge for yourself. You can issue a practice invoice without legal effect on the demo (demo.biurko.io, 7-day access, the KSeF demo environment); an account on app.biurko.io sends invoices to production KSeF. No card, no sales call.

FAQ

Can Biurko replace an accountant? No. Biurko is software for invoicing, KSeF submission, VAT registers and a revenue ledger for lump-sum taxpayers (no KPiR). It does not give tax advice, sign filings or take responsibility for your books. If you need someone accountable for your accounting, you need an accounting firm.

Is Biurko suitable for a foreign company with a Polish subsidiary? It depends on the entity's accounting regime. If the subsidiary is a limited company on full statutory books, you need a full accounting system or a Polish accounting firm. Biurko can still cover the invoicing and KSeF layer next to those books.

Does Biurko handle inventory or marketplace sales? No. There are no stock levels and no native integrations with marketplaces or fiscal printers. For goods-based businesses, iFirma, wFirma or Subiekt are better fits.

What does Biurko cost for an accounting practice? TEAM at PLN 99 net per month gives five users and lets you run up to five companies, each company having its own plan. SCALE at PLN 199 net removes both limits. There is no separate plan for practices: the accountant joins a client's company as a free guest (one seat in every company, on every plan). Annual billing is 20 percent cheaper.

Can I export my data if I leave? Yes. Counterparties, products, sales invoices and the purchase register export to CSV or XLSX at any time. Invoices already submitted to KSeF also remain available in the Ministry of Finance system for 10 years.