From Post-Audit to Proactive Oversight

On the one hand, there is the persistent problem of the VAT gap—the difference between expected and actually collected VAT—which amounts to tens of billions of euros annually in the EU. On the other hand, there are technological capabilities that now make it possible to make invoices, orders, and book entries immediately available digitally for verification.

This approach is known as Continuous Transaction Controls (CTC). Instead of checking for completeness and accuracy only after the fact, tax authorities want to know what is happening before or even as transactions are sent. And in some cases, they even want to approve or block them in advance.

This systemic shift affects companies’ core processes. CTC is not just about VAT compliance. It impacts how organizations create invoices, how ERP systems communicate, how quickly and accurately data is available, and how countries gain control over economic flows. This article discusses the models, technologies, and implications of CTC, drawing on insights from the day-to-day operations of companies that view this not merely as an obligation, but as an opportunity to strengthen their processes.

Why CTC Is Not Just a Technical Requirement

In conversations with clients, we often notice the same knee-jerk reaction: “It’s a new requirement, so let’s quickly figure out the technical solution.”

But that’s too narrow a view. CTC isn’t just a technical add-on. It’s a shift in the relationship between the government and the business community. You no longer share your data voluntarily or periodically; you’re required to report in real time or in advance. This also changes the balance of power. The government becomes the infrastructure manager of your trade data.

At the same time, this shift offers opportunities:

• Automation of tax returns (pre-filling)
• Fraud detection before the supply chain begins
• Improved traceability in supply chains
• Fewer corrections and credit memos afterward
• A uniform digital foundation for international collaboration

Those who take a strategic approach will reap the benefits. Those who merely check off compliance requirements will fall behind.

Four CTC Models and Their Implications

The term CTC is often used as a catch-all, but in reality, there are multiple implementation models. Each has its own implications for processes, technology, and responsibilities.

1. Clearance: Prior Approval

In this model, the government approves the invoice before you send it to your customer. You may only send it after approval. Italy, Mexico, India, and Chile use this model. The invoice receives a unique reference code from the government.

This requires integration with central government systems or with certified service providers that technically facilitate the clearance process. What you’ll notice in practice: these models enforce standardization but leave less room for exceptions.

2. Real-time reporting: immediate submission

Here, you simply send the invoice to the customer yourself, but you must submit the invoice data to the government at the same time or immediately afterward. This is the case, for example, in Spain (SII) and Hungary. The government does not provide prior approval but expects full transparency in real time.

In Hungary, we saw companies struggling with data quality and ERP adjustments: transactions reported too late or incompletely resulted in penalties. Here, “real-time” literally means: no time for correction.

3. Periodic reporting: the basis for pre-filling

Countries such as Portugal and Norway use a model in which you submit data periodically—either daily or monthly. This allows the government to pre-fill VAT returns itself. Within the EU, this model is also part of the first phase of the ViDA plans.

The main impact here lies in consistency: the entire process, from sale to accounting entry, must be logically traceable, because your data will later appear in your own return.

4. Network-based: such as Peppol

We see a unique variation in Belgium: there, the government has been added as the “fifth node” in the Peppol network. All B2B invoices go through Peppol, and the government monitors them. This provides real-time insight without requiring a central platform.

This model is gaining traction because it aligns with existing B2B processes. As a company, you retain your autonomy, but with the assurance that the government is monitoring the process in real time. It is a form of CTC that works well in countries where interoperability and privacy must remain in balance.

Technical Approaches: APIs, Networks, and Control Layers

An important prerequisite for interoperability in CTC environments is the use of harmonized semantic standards. Within Europe, EN 16931 is the leading standard in this regard. This standard defines how an electronic invoice must be structured in terms of content and format so that it is understandable, verifiable, and processable, regardless of the system or country.

In many CTC models, EN 16931 serves as the semantic foundation: it defines the fields, codes, and relationships between data. Combined with syntactic standards such as UBL and Peppol BIS, this creates a robust framework for real-time validation and processing.

For businesses, this means that those already working with invoices structured in accordance with EN 16931 are better prepared to meet international compliance requirements. Behind every CTC model lies a technical architecture. What we see in practice:

• Italy and Hungary use centralized government systems (SDI and NAV) that are accessible via APIs.
• Spain offers SOAP and REST interfaces for the reporting platform.
• In Belgium, Peppol is being expanded with additional validation layers (5-corner model).
• Some countries use certified platforms as intermediaries, such as in Latin America.

In virtually all cases, the following applies:

• Data integrity is crucial: what do you report, when, and how consistently?
• Authentication is performed via PKI certificates: who is authorized to submit reports?
• Middleware is essential if your ERP doesn’t communicate in real time or without errors.

For multinationals with multiple locations, this means: you must be able to handle multiple CTC flows simultaneously, without each country becoming its own compliance project.

Who manages this?

CTC isn’t just being rolled out by national tax authorities. On the contrary, there’s an entire policy infrastructure in place:

• The European Commission places CTC at the center of ViDA (VAT in the Digital Age), where it is part of the broader Digital Reporting Requirements (DRR): a European framework for digital VAT reporting, including real-time reporting obligations, periodic uploads, and pre-filled returns.
• The OECD advises countries on the global harmonization of e-reporting.
• Standards organizations such as CEN, UN/CEFACT, and OpenPeppol are working on interoperable specifications.
• Supplier associations such as EESPA and ERP platforms are involved in impact analyses.

The primary driver remains VAT control, but the ambition extends further: real-time visibility into economic activity, automation of compliance, and even supporting ESG reporting through invoice data.

What does this mean for businesses?

For businesses, a fundamental shift is taking place. Whereas you could previously rely on periodic filings and retroactive corrections, you are now expected to submit transactions accurately, completely, and on time as they occur. In practice, this means that processes, systems, and roles must be scrutinized.

What often becomes apparent in practice:

• ERP systems must be able to communicate in real time. A manual export to Excel is no longer sufficient. This requires API integrations or a middleware layer that can directly retrieve, enrich, and send data.
• Errors are no longer internal matters. An incorrect VAT number or missing data is no longer just an administrative inconvenience but can cause reporting issues or result in penalties. Companies must systematically improve their data quality.
• Validation must take place before transmission. The responsibility lies with the sender. Control mechanisms must therefore shift from the end of the process to real time or even before invoicing.
• Every country has its own model. Companies operating across borders must deal with clearance in Italy, real-time reporting in Hungary, and Peppol-CTC in Belgium. These differences require an infrastructure that isn’t tied to a single standard but rather translates, enriches, and converts data.

Organizations that prepare for this are not building a compliance layer, but a competitive advantage. They are able to respond more quickly to tax changes, as well as use invoice data for procurement analysis, cash flow projections, or ESG reporting. In this context, CTC is not a burden, but a lever for insight.

CTC is the beginning of something bigger

It is now becoming clear that CTC is not an exception, but the forerunner of broader real-time governance. The principle—sharing data with authorities at the time of the transaction—is applicable to many more areas than just VAT.

What you’re already seeing:

• In the customs sector, real-time goods documentation is already in use.
• In statistics, such as at Statistics Netherlands (CBS), accounting systems are directly connected for monthly reporting.
• In public procurement, requirements are emerging for real-time supplier verification and traceable invoices.

In addition, interest is growing in combining tax data with sustainability reporting. Think of automatically linked CO2 data per invoice line, or verifying supply chain transparency based on mandatory transaction reporting. This calls for platforms that not only comply with a single regulation but are also prepared for a layered, interconnected flow of information.

CTC is therefore not an end point. It is the first chapter in a broader digital audit framework. For companies, the question is not whether they need to adapt, but how they can organize their data flows so that they can immediately participate in each new chapter and not be left behind.

We are only at the beginning of a larger systemic change:

• From periodic filing to transaction-based reporting.
• From a national tax model to international data flows.
• From self-reporting to embedded auditing.

CTC is not the end of the line in this process. It is the new normal for every form of reporting. Think of customs, statistics, subsidies, and even supply chain governance. Those who prepare now will strategically position themselves ahead of the curve.

Conclusion

Continuous Transaction Controls are forcing companies to adapt. But those who look beyond the checkbox will see opportunities above all:

• Control over data quality.
• Fewer errors and less risk.
• A single infrastructure for all countries.

Real-world experience shows how differently companies are handling this transformation. Some are hastily building a standalone solution; others are using this moment to strengthen their digital foundation.

That’s exactly what we help organizations do: not with yet another temporary solution, but with a robust digital core that can withstand future requirements. Because real-time reporting isn’t a trend. It’s the new standard.