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Księguś terms of service

The rules for businesses using Księguś. Version of 20 October 2026.

This is a translation for your convenience. Only the Polish text is binding.

§ 1. General provisions

  1. These terms set out the rules for using the Księguś service, available at app.twojksiegus.pl (the Service). They are the terms referred to in Article 8 of the Act of 18 July 2002 on providing services by electronic means (ustawa o świadczeniu usług drogą elektroniczną).
  2. The Service is operated by Volt and Amaranth spółka z ograniczoną odpowiedzialnością, with its registered office in Leszno, ul. 55 Pułku Piechoty 34, 64-100 Leszno, entered in the register of entrepreneurs of the National Court Register (rejestr przedsiębiorców Krajowego Rejestru Sądowego) under KRS number 0000733234, kept by the District Court for Poznań – Nowe Miasto and Wilda in Poznań, 9th Commercial Division of the National Court Register (Sąd Rejonowy Poznań – Nowe Miasto i Wilda w Poznaniu, IX Wydział Gospodarczy KRS), NIP 6972347881, share capital PLN 10,000 (the Provider). Contact: kontakt@twojksiegus.pl.
  3. The Service is intended for businesses. Only a business holding a NIP (tax identification number) may conclude the Agreement. The Service is not intended for consumers within the meaning of Article 221 of the Civil Code (Kodeks cywilny). Specific rules for natural persons running a sole proprietorship are set out in § 11.
  4. Definitions used in these Terms:
    • Customer means a business that has concluded the Agreement with the Provider;
    • User means a natural person who has an account in the Service and acts on behalf of the Customer (e.g. the business owner, an employee or an accountant);
    • Agreement means the agreement for the provision of services by electronic means concluded on the conditions of these Terms;
    • Plan means the scope of Service features available to the Customer (the free Start Plan or a paid Plan);
    • Customer Data means all data that the Customer or its Users enter into the Service or that the Service retrieves on their instruction (e.g. invoices from KSeF, bank statements, data of counterparties and employees);
    • Data Processing Agreement means the agreement on entrusting the processing of personal data, which forms part of the Agreement.

§ 2. What the Service does

  1. The Service helps to run a business’s affairs, in particular to: retrieve invoices from the National e-Invoice System (KSeF) and issue invoices in it, accept invoices sent as a file or a photo, approve invoices for payment, prepare transfer files for import into a bank, load bank statements and match payments, display financial summaries, keep employee records, rotas and working time, and prepare summaries for accounting. The features available depend on the Plan.
  2. The Service is a tool. The Provider is not an accounting office or a tax adviser; it does not keep books, file returns or make transfers. The Customer checks the transfer file and sends it itself, in its own bank. The Customer is responsible for the content of issued invoices, for sending them to KSeF and for tax settlements.
  3. To retrieve and send invoices, the Service needs a KSeF token that the Customer has generated in KSeF. The Customer may at any time remove the token from the Service or revoke it in KSeF.
  4. Data read automatically (from a file, photo, e-mail or statement) may contain errors. The Service always presents invoices that did not come from KSeF for checking by a human. The Customer checks the data before payment and before passing it on to accounting.
  5. The Service uses public administration systems: KSeF, the white list of VAT taxpayers (wykaz podatników VAT, “biała lista”), the REGON register (rejestr REGON) and the exchange rates of the National Bank of Poland (NBP). The Provider is not responsible for their availability or for the data they return.

§ 3. Technical requirements and security

  1. To use the Service you need: a device with internet access, an up-to-date browser (e.g. Chrome, Edge, Firefox, Safari) with JavaScript and cookies enabled, and an e-mail address.
  2. Using services over the internet involves typical risks, such as attempts to obtain passwords by deception (phishing), malicious software on the device or account takeover. The Provider recommends using a long, unique password, enabling two-step login in the account settings and logging in only at app.twojksiegus.pl. The Provider never asks for a password by e-mail or by telephone.
  3. A description of the Service’s safeguards is on the Security page.

§ 4. Account and conclusion of the Agreement

  1. To create an account, you must complete the registration form, accept these Terms and the Data Processing Agreement, and then click the link sent to the e-mail address provided. The Agreement is concluded when the e-mail address is confirmed, for an indefinite period.
  2. The person creating the account declares that they are authorised to act on behalf of the Customer and that the data provided in the form are true.
  3. The owner of the business account may add further Users and assign roles to them. The Customer is responsible for the actions of its Users and for revoking access for persons who have stopped working for it.
  4. A User does not share their password with other persons. The Customer informs the Provider without delay if it suspects that an unauthorised person has gained access to the account.
  5. The following are prohibited: entering unlawful content into the Service, attempting to bypass security measures or to access other people’s data, deliberately overloading the Service, automatically retrieving data in a way that hinders the operation of the Service for others, and reselling access to the Service without the Provider’s consent.

§ 5. Trial period, Plans and payments

  1. After confirming the e-mail address, the Customer receives the full PRO Plan free of charge for 30 days, without providing a card. The trial period is available once per NIP number.
  2. After the trial period, if the Customer does not order a paid Plan, the account moves to the free Start Plan. Start includes retrieving invoices from KSeF and issuing up to 10 sales invoices per month (corrective and pro forma invoices do not count towards the limit).
  3. The current price list and the scope of the Plans are shown in the Service, on the Abonament (Subscription) page. Prices are net prices; VAT at the applicable rate is added to the price. A paid Plan may be paid for monthly or annually.
  4. After a paid Plan is ordered, the Provider issues a pro forma invoice with a 14-day payment term and immediately activates the ordered Plan. Payment is made by bank transfer to the account indicated on the pro forma invoice. If payment is not made on time, the account returns to the Start Plan. After receiving payment, the Provider issues a VAT invoice. The Customer agrees to receive invoices in electronic form, including via KSeF.
  5. 7 days before the end of the paid period, the Provider issues a pro forma invoice for the next period. If it is not paid, the account moves to the Start Plan once 7 days have passed from the end of the paid period.
  6. When a feature ceases to be available in a Plan, the data associated with it are not deleted. They are hidden and return once an appropriate Plan is purchased.
  7. The Provider may change prices for future billing periods by informing the Customer by e-mail at least 30 days in advance. The change does not apply to a period already paid for. A Customer who does not accept the new prices may, before they take effect, cancel the paid Plan or terminate the Agreement.

§ 6. Operation of the Service

  1. The Provider takes care to keep the Service running around the clock but does not guarantee uninterrupted availability. The Provider carries out planned technical work outside working hours where possible and announces it in advance.
  2. The Provider makes encrypted backups of the data every day and stores them with a different provider, in a different data centre.
  3. The Provider develops the Service and may change its features. In doing so, it does not materially restrict the features of a Plan that the Customer has already paid for until the end of the paid period.

§ 7. Customer Data

  1. Customer Data belong to the Customer. The Provider processes them solely to provide the services under this Agreement. It does not sell them or use them for advertising or for its own purposes.
  2. The Provider processes personal data contained in Customer Data (e.g. data of counterparties who are natural persons and data of employees) on behalf of the Customer under the Data Processing Agreement. The Customer is their controller.
  3. The Provider processes the personal data of Users needed to maintain accounts and for billing as a controller, in accordance with the Privacy Policy.
  4. The Customer may at any time download Customer Data using the exports available in the Service, or request that they be handed over by writing to kontakt@twojksiegus.pl.
  5. The Customer is responsible for having the right to enter into the Service the data it enters, in particular the data of its employees.

§ 8. Termination of the Agreement

  1. The Customer may terminate the Agreement at any time, without a notice period, by sending a message to kontakt@twojksiegus.pl from the e-mail address of the owner of the business account. Fees paid for the current period are not refundable, subject to § 11.
  2. Cancelling a paid Plan without terminating the Agreement means moving to the Start Plan after the end of the paid period.
  3. The Provider may terminate the Agreement with 30 days’ notice for a valid reason, in particular because it ceases to operate the Service or because of a change in the law that makes operating it impossible. In that case, the Provider refunds a proportionate part of the fees for the paid, unused period.
  4. The Provider may terminate the Agreement with immediate effect if the Customer or its User seriously breaches these Terms (in particular § 4(5)) and has not ceased the breach despite a request sent by e-mail. No request is needed where the breach threatens the security of the Service or of other Customers’ data.
  5. After termination of the Agreement, the Customer has 30 days to download Customer Data. The Provider then deletes Customer Data from the Service. Data disappear from backups in the normal cycle of their replacement, no later than after 12 months. The Provider retains data that it is itself required to keep by law, e.g. invoices issued to the Customer.

§ 9. Liability

  1. The Provider is liable to the Customer for non-performance or improper performance of the Agreement on general principles, subject to the limitations in this section.
  2. The Provider is not liable for: unavailability or errors of KSeF, bank systems and public registers; data entered by the Customer or its Users; the consequences of not checking data read automatically; the actions of the Customer’s Users; the consequences of disclosing a password or KSeF token to third parties; force majeure events.
  3. The Provider’s liability covers only actual loss (excluding lost profits) and is limited to the amount of fees paid by the Customer in the 12 months before the event giving rise to it or, if the Customer made no payments in that time, to PLN 500.
  4. The limitations in paragraphs 2 and 3 do not apply to damage caused intentionally or to cases where the law does not allow liability to be limited.

§ 10. Complaints

  1. Complaints about the Service may be submitted by e-mail to kontakt@twojksiegus.pl. Please give the business name or NIP, the account e-mail address and a description of the problem.
  2. The Provider replies to a complaint by e-mail within 14 days of receiving it.

§ 11. Natural persons running a business

  1. This section applies to a natural person who concludes the Agreement directly related to their business activity where the content of the Agreement shows that it is not of a professional nature for that person, arising in particular from the subject of their business activity as disclosed in the Central Register and Information on Economic Activity (CEIDG) (Article 38a of the Act of 30 May 2014 on consumer rights (ustawa o prawach konsumenta)).
  2. Such a person may withdraw from the Agreement within 14 days of its conclusion without giving any reason, by sending a statement to kontakt@twojksiegus.pl. If, before that period expires, they ordered a paid Plan and agreed to the start of the service, they pay for the period up to the moment of withdrawal.
  3. Provisions of these Terms that, under the rules on unfair contract terms, are not binding on a consumer are not binding on such a person either. This applies in particular to the limitations of liability in § 9, to the extent that the law does not permit them.

§ 12. Changes to the Terms

  1. The Provider may change these Terms for a valid reason, in particular because of a change in the law, a change in the Service’s features, security considerations or a change of providers.
  2. The Provider informs Customers of a change by e-mail and in the Service at least 14 days before it takes effect. A Customer who does not accept the changes may, before they take effect, terminate the Agreement in accordance with § 8(1), and the Provider refunds the unused part of the fees paid.
  3. Changes required by law or solely beneficial to Customers may take effect earlier.

§ 13. Final provisions

  1. The Agreement is governed by Polish law. Disputes are resolved by the court having jurisdiction over the Provider’s registered office, except for disputes with the persons referred to in § 11.
  2. These Terms are available free of charge on this page, in a form that allows them to be saved and printed.
  3. Translations of the Service into other languages are for information only. The Polish text of the Terms is binding.