Biurko vs inFakt: Which KSeF Tool Fits Your Business?

inFakt is a solid, proven product. It has been on the market for over a decade, belongs to the Visma group, has strong user ratings and supports KSeF on every plan. If you run one company and nothing else concerns you, it will do the job.

The real question is what happens when there is more than one entity, when a limited company sits next to your sole proprietorship, when someone other than the owner issues invoices, or when KSeF stops responding in the middle of a working day. Since 1 April 2026 mandatory e-invoicing has covered effectively all VAT payers (the smallest follow from 1 January 2027), per the Ministry of Finance timeline, so none of those situations is hypothetical any more.

Here is what each tool does, what it costs in four realistic setups, and where Biurko gives you more.

One account instead of one account per company

An inFakt account corresponds to a single company. A second business or a limited company means a second subscription, a second login and a second KSeF configuration.

In Biurko, entities live inside one panel. 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. Each company keeps its own KSeF connection, its own numbering scheme and its own registers, but you switch between them in one click, without logging out.

Roles come with it. You define a role with a specific permission set, so an assistant can issue invoices without sending anything to KSeF or changing the numbering format. A shared password on one account is the most common reason a document reaches KSeF that nobody meant to send, and a submission cannot be taken back.

Invoices and tax filings in the same place

Alongside invoicing, Biurko covers tax settlements:

• sales and purchase VAT registers, with cost categories and JPK markers,

• the revenue ledger and advance payments for lump-sum taxpayers,

• JPK_V7M and JPK_V7K, the annual JPK_EWP, JPK_FA(4) on demand: file download from the SOLO plan, submission to the Ministry with UPO from PRO,

• ZUS contributions for sole proprietors on the lump-sum tax and the KEDU file for DRA (you file the DRA yourself through PUE ZUS),

• a full-year tax obligation calendar with due dates and payment tracking,

• bad debt relief, with proposed corrections surfaced before the deadline passes.

In practice, an invoice issued in the morning lands in the register, in JPK and in the calendar without being retyped anywhere. Purchase import works the other way: documents are pulled from KSeF on a schedule (once you switch it on in company settings), and anything that cannot be mapped unambiguously gets a specific review reason. A settlement invoice referencing several advances, a correction whose original is not in the database, a gross total that disagrees with the sum of the lines: each case looks different and is described differently, instead of one generic "check this" badge.

KSeF as the spine, not a button

Most tools bolted KSeF on as another feature. Biurko was built around it, and that shows in the details that only surface under load.

Certificate authentication. Three paths: Profil Zaufany (the Polish government's trusted profile, the default), your own KSeF certificate uploaded manually as PEM or password-protected P12, and a certificate ordered through Biurko from the Ministry of Finance. The system verifies that the key matches the certificate and that the tax ID in the certificate matches the company, and it tracks the expiry date. We do not support KSeF tokens at all. Under the current rules KSeF tokens expire on 31 December 2026. At consultations on 9 June 2026 the Ministry of Finance proposed keeping them, but no regulation has been adopted yet, so moving to a KSeF certificate is the safer choice.

Offline and emergency modes. An invoice issued while KSeF is unavailable carries the right marker and later enters JPK_V7 flagged OFF. The system remembers that the document is waiting for a KSeF number and closes the loop once the gateway returns.

Errors in plain language. The KSeF gateway returns codes and messages written for integrators. Biurko translates them into a sentence that tells you what to fix on the invoice.

Full document coverage. FA(3) with advance and settlement invoices and every correction type, plus FA_RR and KOR_RR corrections, the VAT RR invoice a buyer issues on behalf of a flat-rate farmer.

An MCP server from the SOLO plan. You can drive the system from an AI assistant: ask about unpaid invoices, issue a document, check a submission status. inFakt offers MCP from the Plus plan upward. In Biurko it starts on the SOLO plan.

Feature comparison

inFakt data comes from its official product pages, as of September 2026. Plan scopes change, so it is worth checking the source before deciding.

Four setups in practice

One sole proprietorship, filing yourself. The SOLO plan (PLN 29 net per month) covers unlimited invoices and KSeF, VAT registers, the revenue ledger for lump-sum taxpayers, JPK file downloads, ZUS contributions for sole proprietors on the lump-sum tax and AI access (MCP). KPiR and the annual PIT return stay outside Biurko. Invoices, KSeF and VAT registers sit in one place, with nothing retyped into a second program.

A sole proprietorship plus a limited company. In a single-company model that means two separate accounts, two subscriptions and two KSeF configurations. In Biurko you run both entities in one panel, with separate KSeF connections and a one-click switch between them; you choose the plan for each company separately.

Three entities and two people in the business. The single-company model means three subscriptions, three sets of credentials and no visibility into who sent what. In Biurko all three entities and both people work in one panel with separated permissions (TEAM gives five users and up to five companies, and each company has its own plan).

An accounting office with 30 clients. Biurko has no separate workspace for accounting offices: 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. A client's purchase invoices come into that company from KSeF if the import is switched on there (it is off by default), instead of being chased over email.

What Biurko does not do

Stated plainly, so there are no surprises after signing up. Biurko is software, not an accounting practice: we do not assign a dedicated accountant, we do not represent you before the tax and social security offices, and we do not carry professional liability for your books. We do not keep KPiR or prepare the annual PIT return. Costs that do not arrive through KSeF can be read from a PDF or a scan by AI (1 AI credit per page, up to 30 pages; the FREE plan has 20 credits a month) or entered manually, and you choose the cost category yourself. There is also no bank integration with automatic tax payments and no recurring invoice scheduler.

Decision checklist

1. Count the entities you manage. Above one, the single-company model starts charging you twice.

2. Check how many people issue invoices and whether each of them should be allowed to send to KSeF.

3. Decide how you authenticate to KSeF. A certificate survives regulatory changes nobody has seen yet.

4. Verify the document types you actually issue: advance, settlement, corrections, FA_RR.

5. Check whether filings and invoices can run without retyping data between two systems.

6. Test your chosen tool on one real month of invoices, not on a single test document.

Summary

inFakt is a decent product and for some one-person businesses it is entirely enough. Biurko offers something different: the same invoicing and KSeF, plus VAT registers, JPK, the revenue ledger for lump-sum taxpayers and ZUS contributions for sole proprietors on the lump-sum tax in one panel, several companies under one login, roles for your team, certificates instead of tokens, offline mode handling and AI assistant control from the SOLO plan. KPiR and the annual PIT return stay outside Biurko, so if you keep your books on the tax scale or the flat tax, check that before choosing.

Create a free Biurko account and connect your first company to KSeF. The FREE plan needs no card, has no time limit and includes unlimited invoices and KSeF submissions.

FAQ

Is Biurko an alternative to inFakt?

Partly. Biurko covers invoicing, KSeF, VAT registers, the revenue ledger for lump-sum taxpayers and JPK files, and adds a multi-company panel with roles. It does not keep KPiR or prepare the annual PIT return, and it does not offer a dedicated accountant service.

Can I try Biurko before committing?

Yes. The FREE plan needs no card and no contract. You connect one company to KSeF and run the whole cycle, issuing an invoice, sending it, importing purchases and posting to the register, before paying anything. To practise without legal effect, use 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.

Can I run several companies on one account?

In Biurko, yes: up to five companies on TEAM and no limit on SCALE, each with its own plan, KSeF connection and numbering. An inFakt account is tied to one company, so every additional entity means another subscription.

Is Biurko suitable for a limited company?

Yes. Invoicing, KSeF, VAT registers and JPK work the same way for a company as for a sole trader, and the multi-company panel with roles pays off wherever more than one person issues invoices.

Do both systems support FA(3)?

Yes. FA(3) has been mandatory in KSeF since 1 February 2026, so it is a requirement rather than an advantage. Differences show up on rarer documents such as FA_RR and settlement corrections, and in how offline and emergency modes are handled.