Verifactu: FAQs to know before mandatory compliance for software developers

ℹ️ The answers provided by fiskaly Iberia S.L. are for informational purposes only and are not legally binding. fiskaly Iberia S.L. is not a tax consultancy firm but a developer of tax compliance software, so the information provided is advisory in nature. In any case, any activity related to invoicing and taxation should always be consulted with a tax advisor who understands the specific implications of each regulation for individual businesses or professionals.

Key aspects to comply with Verifactu

As you already know, the deadline for mandatory compliance with Verifactu for software developers is July 29, 2025. And although companies and self-employed individuals will not have to meet Verifactu’s technical requirements until January or July 2026, any third-party software they use must already comply with the regulation by then.

Despite the fast-approaching compliance deadline, we are still receiving a large number of questions about Verifactu, its implementation, and its implications over the coming months.

That’s why we’ve put together this article, compiling the most common questions and inquiries we receive, to help you more easily find the information you need. The questions are organized by topic, with clear and up-to-date answers aligned with the latest updates from the official AEAT regulation. Whether you're a software developer, manage a company, or work as a self-employed professional, here you’ll find the key information to prepare with confidence and in good time.

The importance of a Verifactu API & a partner specialized in fiscal compliance

We know that understanding the requirements is just the first step. What really matters is how to implement them smoothly and efficiently in your invoicing system.

At fiskaly, fiscal compliance is our core. That's why we’ve developed SIGN ES, our Verifactu API designed specifically to help you comply without changing your system architecture or investing months in development. With SIGN ES you can:

• Easily integrate all technical requirements set by the AEAT
• Automatically generate Verifactu records, QR codes, CSV, and the hash chain
• Securely submit data to the AEAT in full compliance
• Manage certificates internally, with no complexity for your end user
• Ensure the security and protection of your company’s and clients’ sensitive data, using a solution certified under ISO 27001 and ISO 9001
• Comply not only with Verifactu, but also with TicketBAI in the Basque Country, the upcoming tax legislation in Navarra, and the mandatory B2B e-invoicing under Spain’s Ley Crea y Crece