Terms of Use

Defines the key terms used throughout: the Service (the Tezga eKasa software), the User (a company or sole trader), the Account, the Operator, ESIR, PFR and V-PFR/L-PFR, the security element, SEF and User Content.

Tezga eKasa is an ESIR approved by the Serbian Tax Administration (decision no. 000-092-00-00123/2026-0000 of 3 July 2026, model 1.1, IB 1597). It runs in a browser or as an app and fiscalizes through the Tax Administration V-PFR using a security element the User provides. It is a tool, not an accounting or tax advisory service.

Only businesses (companies, sole traders and other legal entities) may use Tezga within their registered activity. It is not offered to consumers, so consumer rights such as the 14-day withdrawal do not apply. One account belongs to one taxpayer, and sharing, renting or reselling access is forbidden.

The User creates an account with accurate company data and expressly accepts these Terms and the Privacy Policy at registration. Go Simple records the document version, date, time and IP address of the consent as proof of the contract. The User keeps company data current and protects its login credentials.

The Service has three roles: administrator, manager and cashier. Each operator must have their own username, because the activity log must show who did what; account sharing is banned. The administrator grants the least necessary rights and promptly revokes access when someone leaves.

The User must issue a fiscal receipt for every retail sale, at the moment of sale and regardless of the payment method. Items, quantities, prices, discounts and tax labels must be entered correctly, and the chosen payment method must match how the sale was actually settled. Issuing receipts that do not reflect real turnover is forbidden.

The Service supports the receipt types defined for ESIR (sale, advance, pro forma, copy and training). A pro forma invoice has no tax effect, and a receipt issued in training mode has no tax effect and must never be used in real trade. Misusing training mode for actual sales is a material breach and grounds for immediate suspension.

A refund returns part or all of a previously issued receipt and, by regulation, requires identifying the customer, so the Service asks for identity-document data. A cancellation voids a receipt in full and needs no customer identification. The User picks the process that matches the real event and keeps the supporting documentation.

The User registers its business premises with the Tax Administration and keeps the data in the Service consistent with what was registered. The number of tills and premises in use must match the chosen plan. Entering data in the Service does not replace the official registration of premises.

The User obtains the security element from the Tax Administration for its premises. By entering the certificate, password, PAK or PIN, the User authorizes Go Simple to store them encrypted (AES-256-GCM) and use them solely to issue fiscal receipts on the User's behalf; they are never shown back or used for anything else. Support will never ask for the PIN.

The Service needs a stable internet connection provided by the User. With V-PFR a fiscal receipt cannot be issued without a connection, so sales must stop until it returns; work during outages is enabled only by a local processor (section 12). Outages of the Tax Administration systems are not Go Simple's fault.

The law lets the obligor choose between a local processor (L-PFR), which issues receipts offline, and the Tax Administration V-PFR, which needs a constant connection. For sales in physical premises an L-PFR is recommended; the User obtains and maintains the device, smart card, reader and power, and one processor is used per premises. The Service never switches processors on its own.

The fiscalization obligor is the User, not Go Simple; Tezga is only the tool it uses. A User selling at retail in physical premises must, besides V-PFR, keep at least one device with a local processor (L-PFR) in each premises (Law on Fiscalization, art. 6(4)), except for retail sold exclusively online.

The User must promptly check issued receipts, reports and calculations and raise any complaint about a Service error without delay, and at the latest within 30 days. A timely complaint is the condition for correcting an error while that is still possible. A complaint does not defer payment of a due subscription.

The Service can send and receive e-invoices through SEF to the extent the plan covers. The User provides the SEF access key and remains responsible for the statutory deadlines; reminders in the Service are help, not a substitute. The availability and behavior of SEF are the responsibility of its operator.

The Service can import bank statements to match payments against receipts and invoices. The User is responsible for the accuracy of account data and for the right to use it. Matching is an aid: the final check of collection and the bookkeeping rest with the User and its accountant, and the Service never initiates payments.

The Service offers an API and integrations to the extent the plan covers; the API key is the User's secret and anything done with a valid key counts as the User's action. An integrator must not draw its own fiscal receipt or alter the data and QR code received from the processor, and the User is responsible for its integrations and for how the API is used.

The Service is offered in plans whose content and price are published on the site; the plan sets which functions are available and in what volume (tills, premises, users, API requests). Upgrades take effect immediately and downgrades from the next billing period, and reasonable technical limits may be introduced with prior notice.

Prices are stated in dinars (RSD) and the subscription is paid in advance for the plan's period. Access is unlocked once the payment is recorded. Prices may change with at least 30 days notice, effective from the next billing period, without changing a period already paid.

If the subscription is not renewed, the account's working functions are locked, but data is not deleted immediately (see section 34). Overdue amounts accrue statutory default interest from the due date, and the documented costs of reminders and collection are borne by the User.

Go Simple aims for continuous availability but does not guarantee uninterrupted operation; the Service is provided with reasonable professional care rather than a fixed uptime guarantee unless separately agreed in writing. Planned maintenance is announced in advance when possible, and urgent security work may be done without prior notice.

Support is provided in Serbian, by email and phone on business days. It covers help with using the Service and fixing Service errors, but not accounting or tax advice, data entry on the User's behalf, or maintenance of the User's equipment. Reported errors are handled by severity, first what prevents issuing receipts.

Parts of the Service depend on systems Go Simple does not control: V-PFR and other Tax Administration systems, SEF, banks, payment operators, internet providers and app stores. If one of them fails or changes its rules, that part of the Service may be unavailable; this is not Go Simple's fault and gives no right to compensation, though Go Simple will make a reasonable effort to reduce the impact.

User Content remains the User's property; Go Simple receives only a limited right to store and process it as needed to provide the Service. Go Simple makes regular backups, but the User must also take the exports the Service offers, since a backup protects the system and does not replace the User's own archive. Aggregated, anonymized usage data may be used to improve the Service.

For data Go Simple processes for its own purposes (account, contact person, billing) it is the controller, as described in the Privacy Policy. For data the User enters about its customers and staff, Go Simple is the processor and the User is the controller, under the Data Processing Agreement, which is part of these Terms. The User must give the required notice and have a valid legal basis.

Each party keeps the other's non-public information confidential and uses it only to perform the contract. The duty continues after termination until the information becomes public without a breach, and does not prevent disclosure required by law or by a competent authority, with notice to the other party where allowed.

Go Simple and the people working on the platform have no insight into the User's business data: turnover, receipts, customers, products, prices or bank statements. For support and monitoring only technical data is processed (whether fiscalization works, connection status, document counts, errors, subscription). Access to business content is possible only when the User expressly requests and enables it to solve a specific problem, and lasts only while that problem lasts.

The software, source code, design, the Tezga name and mark and the documentation remain the property of Go Simple or its licensors; the User gets a non-exclusive, non-transferable right to use the Service for its own business during the subscription. Copying, reverse engineering, reselling access and building a competing product are forbidden, and Go Simple may freely use any improvement the User suggests.

The Service must not be used contrary to Serbian law, to evade taxes, to show false turnover, to endanger the security and stability of the system, or for trade that is legally banned or not allowed on card networks. The User warrants that it is not subject to restrictive measures. A breach here is grounds for immediate suspension and for termination without notice.

Go Simple may use the User's business name and mark as a reference only with the User's prior consent, which can be withdrawn at any time with effect for the future.

The Service is provided with professional care but without a guarantee of error-free, uninterrupted operation. Go Simple is not liable for tax or misdemeanor consequences arising from the User's own data, missed deadlines, misuse or other conduct, nor for third-party outages (section 23). Where Go Simple is at fault, its total annual liability is capped at the subscription paid in the preceding twelve months. This cap does not apply to intent, gross negligence, harm to life and body, or where mandatory law forbids limitation.

If a third party or an authority makes a claim against Go Simple because of the content the User entered, the way the User uses the Service, or a breach of sections 3, 7, 17 and 29, the User must notify Go Simple and reimburse the justified costs and damage that follow, except to the extent the claim results from Go Simple's own fault.

The User may terminate at any time by email, effective from the end of the paid period. Go Simple may suspend an account without prior notice on reasonable suspicion of abuse or breach of sections 3, 7 or 29, with notice immediately after. Go Simple may terminate with 30 days notice, or without notice for an uncured material breach or unpaid subscription.

After termination, User Content stays available for download for at least 30 days, after which it is deleted or anonymized, except data Go Simple must keep longer by law or for a legal claim. Earlier deletion is possible on the User's written request after it confirms it has taken everything it needs. Deletion from the Service does not release the User from its own retention duties.

Notices are delivered by email to the address in the account, or shown in the Service, and are treated as duly served. The User keeps that address accurate and accessible and bears the consequences of not receiving notices sent to a wrong or unavailable address. A notice is deemed received on the next business day.

The User may not assign this contract to a third party without Go Simple's prior written consent, which will not be unreasonably withheld. Go Simple may assign it to a legal successor or an affiliate, with notice to the User, provided the User's rights are not diminished.

Functions may be added, changed or withdrawn; the withdrawal of a function essential to a plan is announced at least 30 days ahead. These Terms may change with at least 15 days notice, and each version carries a version mark and effective date. Continued use after a change means acceptance, and changes required by law may take effect sooner.

Neither party is liable for non-performance caused by an event beyond its reasonable control (natural disasters, war, strikes, power or internet outages, an authority's decision, a major failure of the underlying infrastructure). The affected party must notify the other without delay and make a reasonable effort to reduce the consequences.

These Terms, together with the documents named in the introduction and the description of the chosen plan, form the whole agreement and replace any earlier arrangements on the same subject. A failure to invoke a right is not a waiver of it, and the invalidity of one provision does not void the contract as a whole.

The law of the Republic of Serbia applies. The parties will first try to settle any dispute amicably within 30 days of a written notice; if they do not succeed, the competent court in Belgrade has jurisdiction.

Go Simple, Ivan Dabetic, sole trader, Trgovacka 1, 11307 Bolec, Republic of Serbia; company no. 68389631, PIB 115468360, activity code 7410. Email podrska@tezgafiskal.com and ivan@gosimple.agency, phone 060 0919 029, website pos.narbiz.com.