Verifactu API: what to consider before integrating a compliance solution?

Camille Mendonça

Fiscalization Expert Spain

3/3/20253 min read

Camille focuses on the Spain market as Marketing & PR Manager. With an eye for storytelling, she specializes in simplifying fiscal topics around TicketBAI, Veri*Factu, and e-invoicing, to foster transparency and compliance in an engaging way.

The implementation of the Verifactu regulation, part of the Anti-Fraud Law, marks a turning point in tax compliance in Spain. With new technical requirements and significant penalties for non-compliance, the first to adapt will be software developers and vendors, POS, and ERP providers.

We explore key factors to consider when integrating a solution to comply with the regulation, ensuring a smooth transition and avoiding penalties.

Invoicing software and new technical requirements

The Anti-Fraud Law and the Verifactu regulation aim to ensure transparency and traceability in invoicing records to combat tax fraud. As of July 2025, manufacturers and providers of invoicing software, ERP, and POS systems in Spain must comply with a set of technical requirements mandated by the Spanish Tax Agency (AEAT), including:

Digitally signing invoicing records to ensure their authenticity.
Generating and submitting records to the Tax Agency in real time or with a chained hash.
Generating a QR code on invoices to facilitate verification.
Ensuring security and control through secure communication protocols and immutable data storage.
Keeping anti-fraud software up to date according to Tax Agency's evolving technical requirements.

These new requirements demand that software developers and vendors update their systems by July 29, 2025. But what are the main challenges they face in this adaptation?

Verifactu: challenges for software developers and vendors

For invoicing, ERP, and POS software developers, Verifactu is not just a one-time update—it requires ongoing adaptation and updates to the systems they provide to their clients, including:

Ensuring initial technical compliance: updating key functionalities to meet the regulation’s requirements.
Keeping software constantly updated: software providers must ensure their system remains compliant with AEAT updates.
Protecting client data: implementing security protocols to safeguard tax data and prevent manipulation of records.

Given these challenges, many developers are turning to collaborative fiscal solutions, such as APIs, which simplify compliance and reduce technical costs.

Why Choose an API-Based Solution?

Integrating an API offers multiple benefits:

Saves time and development costs
Automatically stays compliant with regulatory updates
Ensures compatibility with existing systems
Simplifies integration across multiple platforms

What to consider when choosing a solution to comply with Verifactu?

Choosing the right compliance solution can make a significant difference in ensuring a smooth integration. Here are the key aspects to consider:

Ease of integration: look for solutions that integrate quickly and easily with your existing software. An API with clear documentation and testing environments, like SIGN ES, can make this process much smoother.
Automatic updates: ensure the chosen solution provides automatic updates to maintain compliance with future regulatory changes.
Security and data protection: fiscal data is highly sensitive. Choose a solution that adheres to high security and privacy standards to minimize the risk of data breaches.
Specialized technical support: having a team specialized in fiscal compliance and strong technical support is essential to keeping up with tax regulations, allowing businesses to focus on their core operations.

The importance of partnering with an official Tax Agency Social Collaborator

While the regulation does not mandate certification for compliance solutions, partnering with an AEAT-registered Social Collaborator streamlines the integration process and ensures accurate and secure data transmission to the Spanish Tax Agency.

fiskaly is a Spanish Tax Agency Social Collaborator for Verifactu file submissions, enabling a simpler, more secure, and validated integration without requiring individual digital certificates from clients.

SIGN ES: an API to ensure Verifactu compliance

Adapting software to comply with Verifactu doesn’t have to be a challenge. Our SIGN ES solution allows any invoicing, ERP, or POS software to meet all technical requirements with a single API integration.

With SIGN ES, developers can offer their clients an optimized solution that ensures seamless tax compliance and robust data protection. We handle the compliance process so you can focus on growing your business.