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, 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 covers five companies and five users, SCALE has no company or user limit. 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
Biurko runs the full tax cycle alongside invoicing:
sales and purchase VAT registers, with cost categories and JPK markers,
KPiR and the revenue ledger for lump-sum taxpayers,
JPK_V7M and JPK_V7K, the annual JPK_EWP, JPK_FA(4) on demand,
the annual PIT return,
ZUS DRA as a KEDU collection, broken down contribution by contribution,
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, 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. Two paths: Profil Zaufany (the Polish government's trusted profile) and a KSeF certificate uploaded manually as PEM or password-protected P12. 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 use tokens at all. Their future is still under Ministry of Finance consultation from June 2026 and has not been settled in law, while a certificate stays stable whichever way that goes.
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 in every 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 free plan.
Feature comparison
Feature inFakt Biurko KSeF sending and receiving yes, all plans yes, all plans KSeF certificate authentication not publicly documented yes (PEM, P12) plus Profil Zaufany Offline24 and emergency mode in the data model not publicly documented yes, with the OFF marker in JPK_V7 Companies per account one 5 on TEAM, unlimited on SCALE Roles and permissions collaborator access custom roles with permission sets KPiR and revenue ledger yes, on accounting plans yes Annual PIT return yes, on accounting plans yes JPK_V7, JPK_EWP, JPK_FA yes yes ZUS DRA yes, on accounting plans yes Bad debt relief not publicly documented yes, with proposed corrections FA_RR (flat-rate farmer) not publicly documented yes MCP server Plus plan and above all plans Interface languages Polish Polish, English, Ukrainian Free plan not publicly documented yes, FREE
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 covers unlimited invoices, unlimited KSeF, VAT registers, KPiR or the revenue ledger, JPK, the annual PIT return and DRA. All 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 both entities fit inside TEAM, in one panel, with a shared contractor database and separate KSeF connections.
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. The TEAM plan covers all three entities, both people and separated permissions.
An accounting office with 30 clients. The SCALE plan, with no company or user limit. Thirty separate KSeF integrations collapse into one connection list, and client purchase invoices arrive automatically 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. Costs that do not arrive through KSeF are entered manually, because PDF field recognition is on the roadmap rather than in the product. There is also no bank integration with automatic tax payments and no recurring invoice scheduler.
Decision checklist
Count the entities you manage. Above one, the single-company model starts charging you twice.
Check how many people issue invoices and whether each of them should be allowed to send to KSeF.
Decide how you authenticate to KSeF. A certificate survives regulatory changes nobody has seen yet.
Verify the document types you actually issue: advance, settlement, corrections, FA_RR.
Check whether filings and invoices can run without retyping data between two systems.
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 simply offers more: the same invoicing and KSeF, plus KPiR, PIT, JPK and ZUS in one panel, several entities on one account, roles for your team, certificates instead of tokens, offline mode handling and AI assistant control from the free plan onward. It works the same way for a sole proprietorship and for a limited company.
Create a free Biurko account and connect your first company to KSeF. The FREE plan needs no card, and you can run the full document cycle before paying anything.
FAQ
Is Biurko an alternative to inFakt?
Yes. Biurko covers invoicing, KSeF, VAT registers, KPiR and the revenue ledger, JPK files, the annual PIT return and ZUS DRA, the same filing scope, and adds a multi-company panel with roles. What we do not offer is 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.
Can I run several companies on one account?
In Biurko, yes: five entities on TEAM and no limit on SCALE, each with its own 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.