Office and accounting tools
in one place

Pull e-invoices from KSeF, calculate currency rates per NBP, check tax interest and compare taxation forms — all in your browser, no install.

How will you use R4 Biuro?

Choose your path — we’ll tailor the tools and the initial setup of the app. You can always change this later in settings.

Everything an accounting office needs

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KSeF Explorer

Pull and browse invoices from the National e-Invoice System. Token + certificate auth (.p12 / .pfx / PEM).

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NBP exchange rates

Current and historical NBP mid-market rates. Converter using the day-before-transaction rate.

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FX differences

Compute exchange-rate differences between invoice date and payment date. PDF export.

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Tax interest

Tax interest calculator using the current statutory rate (currently 10.50%).

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Taxation forms

Compare progressive, flat-rate and lump-sum taxation — an interactive calculator for sole proprietors.

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Payroll calculator

Gross/net payroll figures including ZUS contributions, income tax and tax-deductible expenses.

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Multi-organisation account

Manage multiple companies from one account. Roles: Org Admin, Approver, Member.

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Import costs

Import settlement covering customs duty, transport, handling fees and the NBP rate.

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Ideas board

Submit and vote on new features. Your vote shapes the product roadmap.

Start free. No credit card.

The free plan covers every basic tool. Pro unlocks KSeF Explorer and more.

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