Behind the Scenes of Android Fiscalization: How Fiscal Solutions Built Its Mobile Fiscal Service

Fiscal Solutions' October 2026 Retail Compliance Forum offered a behind-the-scenes look at developing fiscalization software for Android devices. The session explored the journey from the first proof of concept to a multi-country solution, including technical challenges, software architecture and lessons learned.

As retail technology continues to evolve, mobile devices are becoming an increasingly important part of modern point-of-sale (POS) environments. However, bringing fiscalization to mobile platforms is not as simple as adapting existing software to a smaller screen. It requires careful planning, reliable technical solutions and a detailed understanding of different countries' fiscal requirements.

This was the main topic of Fiscal Solutions' Retail Compliance Forum held in October 2026, where Boris, an Android developer at Fiscal Solutions, shared his experience developing the company's Mobile Fiscal Service (MFS).

The forum also marked the introduction of the new Retail Compliance Forum concept, designed to provide practical knowledge, technical insights and real development experiences rather than focusing only on product presentations.

Why Is Mobile Fiscalization Becoming More Important?

While POS systems and mobile devices have changed significantly, many fundamental fiscal requirements have remained relatively similar. Transaction recording, fiscal receipts, secure data storage and reporting remain essential parts of fiscalization. The challenge today is connecting these established requirements with modern technologies such as cloud computing, mobile applications and Android-based POS solutions.

Fiscal Solutions developed its products to address four major challenges: understanding fiscal regulations, managing certification requirements, implementing operational fiscalization processes and providing support during audits and everyday operations. Its fiscal middleware connects POS applications with country-specific fiscal requirements, whether these involve communication with tax authorities, fiscal devices or other mandatory systems.

The development of Mobile Fiscal Service represents another step in adapting fiscalization technology to modern retail environments.

How Did the Android Fiscalization Project Begin?

One of the first decisions Fiscal Solutions faced was whether to build its Android solution internally or purchase an existing application. Building an entirely new solution would require significant investment, while finding suitable software on the market was difficult because of the specialized nature of fiscalization.

The company therefore chose a third option: developing a proof of concept with the support of an external development partner.

The initial objective was straightforward—to demonstrate that fiscalization could operate successfully on Android devices.

France became the first country implemented through the Android application. After the initial proof of concept proved successful, Fiscal Solutions continued developing the solution internally. Austria and Germany followed, while the Czech Republic was identified as a current development focus during the forum.

However, proving that the application could process fiscal transactions was only the beginning. The next challenge was transforming the initial solution into reliable software that could be maintained, tested and expanded to additional countries.

How Does Mobile Fiscal Service Work Across Different Platforms?

Fiscal Solutions already had fiscalization solutions operating on Windows, Linux and cloud environments.

The objective was to introduce Android as another supported platform while maintaining consistent functionality across its solutions.

From the customer's perspective, the platform should not change how fiscalization works. A POS application sends a transaction request to the fiscal service, which processes the transaction and returns the required response. The POS application can then use that response to complete the transaction and issue a receipt. To achieve this consistency, Fiscal Solutions focused on maintaining the same API behavior across its Local Fiscal Service, Cloud Fiscal Service and Mobile Fiscal Service. This presented a technical challenge because the existing solutions used .NET technology and operated in environments designed to support continuous server processes. Android devices, however, manage applications and background processes differently.

Why Was Modular Architecture Essential for Supporting Multiple Countries?

One of the most important lessons from the project concerned software architecture.

The original proof of concept was primarily designed to demonstrate that Android fiscalization could work. It was not initially structured for supporting several countries with different legal requirements. As additional countries were introduced, the development team recognized the need to separate common functionality from country-specific fiscal logic. The solution was to move from a monolithic structure toward a modular architecture.

Common functionality, including HTTP communication, request validation, configuration, local storage, synchronization and monitoring, was moved into a shared core. Country-specific modules were then developed to implement the requirements applicable in individual jurisdictions.

This approach offers several advantages. Changes to German fiscalization requirements, for example, should not interfere with the functionality already implemented for France or Austria. Although the modules share the same core, each country receives its own Android installation package (APK), combining a particular core version with the relevant country module. This also allows the development team to manage versions, updates and testing separately.

What Makes Fiscalization on Android Technically Challenging?

Unlike desktop computers or servers, Android devices are designed to conserve battery power and manage system resources. The operating system can stop background processes when memory becomes limited or battery levels become critically low.

For ordinary applications, this behavior may be inconvenient. For fiscalization software, it presents a more serious operational risk because the fiscal service must remain available to process POS transactions. To address this issue, Fiscal Solutions implemented a foreground service, allowing Mobile Fiscal Service to continue operating when users switch to another application or lock the device.

The presentation compared this mechanism with music applications that continue playing audio in the background. Additional monitoring and watchdog mechanisms help detect service interruptions and restart the application when necessary. The solution is also designed to reactivate the fiscal service after a device restart. However, Android's operating system still retains control over application processes, making complete prevention of interruptions impossible.

For this reason, the development team also focused on protecting transaction data. Transactions are processed and stored locally, with mechanisms designed to preserve transaction consistency if the service stops unexpectedly. Once the service resumes, locally stored data can be synchronized with Fiscal Solutions' cloud services. According to the presentation, these interruption scenarios had not caused problems in production, but they remain part of the company's testing and reliability strategy.

How Are Data Security, Offline Operation and Device Configuration Managed?

Reliable transaction storage was another important development priority.

Mobile Fiscal Service follows a local-first approach, storing transaction records on the device before synchronizing them with central services. The application can also support offline fiscalization in countries where legislation permits it. However, internet connectivity is still required for certain activities, including initial configuration.

The development team also introduced mechanisms to identify potentially problematic Android settings, such as battery optimization and disabled service-persistence functionality. Users can receive warnings and guidance for adjusting these settings to improve the application's reliability. Another practical feature is QR-code-based configuration. Instead of manually entering configuration details for every device, users can scan a QR code to configure the application automatically.

This can be particularly useful for retailers operating large numbers of POS terminals, where manual configuration would require considerable time and effort.

What Were the Most Important Lessons Learned?

During the forum, Boris highlighted several lessons from the development process.

The first was the importance of testing. While the initial proof of concept focused on establishing functionality, the production solution required a much more comprehensive testing strategy. The team subsequently introduced unit tests, integration tests, end-to-end tests and manual testing to reduce the risk of errors.

The second lesson concerned the importance of fiscalization expertise. For example, the team discovered during testing that some country-specific requirements involve more than two decimal places. An initial assumption about decimal precision caused problems in testing, demonstrating how easily developers unfamiliar with fiscal regulations can overlook important requirements.

The third lesson was that software architecture must evolve alongside the product. The transition from a monolithic to a modular architecture was not completed immediately and remained an ongoing process at the time of the forum.

The development team also emphasized the need to balance delivery deadlines with long-term software quality. Rather than attempting to build a perfect solution from the beginning, the company chose to prove the concept first and improve the architecture, testing and reliability as the product developed.

What Comes Next for Mobile Fiscalization?

During the question-and-answer session, participants also asked whether Fiscal Solutions planned to support iOS.

The company confirmed that it was investigating the possibility, particularly because some customers had expressed interest.

However, iOS presents additional technical restrictions, and no implementation commitment or release date was announced.

For Android, the company's continuing priorities include maintaining application stability, supporting additional countries, improving the modular architecture and adapting to new operating system requirements.

Connecting Traditional Fiscal Requirements With Modern Retail Technology

The October Retail Compliance Forum demonstrated that developing mobile fiscalization software involves much more than making an application compatible with Android.

The real challenge is ensuring that fiscal transactions are processed accurately and securely while maintaining reliable operation across different devices, software platforms and national regulatory environments.

The experience shared by Fiscal Solutions also highlighted the importance of combining technical development expertise with detailed knowledge of fiscal regulations.

For retailers and POS software providers, mobile fiscalization creates opportunities for more flexible retail environments. However, successful implementation depends on dependable transaction processing, appropriate offline functionality, effective testing and careful management of country-specific compliance requirements.

As mobile POS technology continues to develop, solutions such as Mobile Fiscal Service illustrate how established fiscalization requirements can be integrated into modern retail systems without compromising compliance or reliability.

Ema Stamenković  Portal Manager  Linkedin profile