Everything you need to know about Tax Compliance in Spain for 2025

Rocío Arquiola

Fiscalization Expert Spain

1/30/202512 min read

As the Marketing & PR Manager for Spain at fiskaly, Rocío focuses on the Spanish market. By simplifying fiscalization around TicketBAI, Veri*Factu + B2B e-invoices, she enhances transparency and compliance in the business community.

The fiscal system in Spain is complex and currently undergoing significant digitalization. The country has two tax regimes: the ordinary and the foral. This means there are regional tax authorities in the Basque Country and Navarra, while the Spanish Tax Agency (AEAT) oversees taxation for the rest of Spain.

To align with the latest European directives on preventing tax fraud, promoting digitalization, and reducing payment delays, Spain has introduced several new laws. These include the Anti-Fraud Law and the Verifactu system at the national level, except for the Basque Country, which has its own TicketBAI regulation, and Navarra, which is developing its own fiscal legislation. Additionally, these regulations will coexist with the Crea y Crece Law, which mandates the use of e-invoicing for B2B transactions, and the existing Immediate Supply of Information (SII, in Spanish) system.

Before delving into each regulation, you might be wondering about something more fundamental: what is fiscalization? This term is not commonly heard in Spain compared to other European countries. Let’s dive in!

What does fiscalization mean?

Fiscalization is the seamless recording of transactions and anti-tamper protection of transaction logs in POS systems. The requirements are set by the legislation of individual countries or administrative regions.

In simpler terms, it's a method to ensure that all companies follow the same rules, promoting transparency in both business and government finances. It also establishes consistent procedures for handling invoices and tax reporting.

At fiskaly, we frequently talk about fiscalization, drawing from our experience in other European markets, rather than simply tax compliance. Our fiscalization software not only facilitates compliance with regulations but also reduces the likelihood of penalties, benefiting companies, professionals, and tax authorities alike.

Fiscal regulations in Spain: what to expect in 2025 and 2026?

Fiscalization in Spain: Anti-Fraud Law (Verifactu)

The Anti-Fraud Law 11/2021, enacted on July 9, introduces measures to prevent and combat tax fraud in Spain. A key component is the introduction of Verifactu systems, designed to prevent the manipulation and destruction of invoicing records.

To comply with Verifactu, all billing software operating in Spain must:

Prevent the modification and destruction of billing records during invoicing.
Electronically sign invoices or send all billing records to the Spanish Tax Agency (AEAT).

The law outlines specific requirements for Verifactu-compliant software, which must be used by businesses and professionals when issuing ordinary and simplified invoices. These requirements include:

Generating an XML file for each transaction, recording both issued and canceled invoices.
Chaining invoices sequentially to ensure traceability and prevent tampering.
Allowing billing records to be sent to the AEAT, either automatically or upon request during an audit.
Electronically signing invoices if they are not directly submitted to the AEAT.

Verifactu implementation timeline

The Ministerial Order detailing Verifactu’s technical requirements was approved on October 28, 2024. This triggered a 9-month adaptation period for software developers and vendors, who must update their systems by July 29, 2025. While the AEAT has not confirmed the exact enforcement date for taxpayers, it is expected to begin in 2026.

Implications for invoicing software developers and taxpayers

Businesses and professionals will need to update their management, billing, and accounting systems to meet AEAT requirements. However, the responsibility does not rest solely on taxpayers; software developers and providers must also comply with the standards set by the regulation.

Penalties for non-compliance are strict. Businesses using non-compliant software could face fines of up to €50,000. Meanwhile, developers and providers who fail to update their systems to meet Verifactu requirements may face fines of up to €150,000 per client and fiscal year, emphasizing the importance of implementing compliant solutions from the outset.

Verifactu API

If your business is based in Spain (excluding the Basque Country and Navarra) and you need to know whether you must comply with this new regulation, when, and how, contact us. Our SIGN ES API meets Verifactu and TicketBAI requirements.

Integrating our Verifactu API into your billing software, POS, or ERP system is straightforward, whether you’re a retailer, software developer, ISV, or vendor of management and billing software. Learn more about fiskaly’s Verifactu API here.

Fiscalization in the Basque Country: TicketBAI

TicketBAI is a mandatory system in the Basque Country aimed at preventing tax fraud by recording and transmitting invoices to tax authorities. In Álava and Gipuzkoa, 99% of businesses already comply, while in Bizkaia, implementation is being phased in under the Batuz system until 2026.

TicketBAI requirements include:

Using registered, compliant software to ensure invoices cannot be tampered with.
Including a unique TBAI identification code and QR code on all invoices.
Generating electronically signed XML files for each transaction and submitting them to regional tax authorities.

TicketBAI API

If your business is based in the Basque Country and you need a solution to comply with TicketBAI without changing your billing system, we can help. Our TicketBAI API integrates easily with POS, ERP, or other billing systems. Learn more about fiskaly’s TicketBAI API here.

Fiscalization for big companies: Immediate Supply of Information (Suministro Inmediato de Información or SII)

The Immediate Supply of Information (SII), in effect since 2017, will remain mandatory in 2025 for large enterprises, those included in VAT groups, and entities registered in the REDEME system (monthly VAT declarations). This system allows for near real-time tracking of VAT records via the Spanish Tax Agency (AEAT) platform.

The SII is mandatory for:

Companies, businesses, and taxpayers based in Spain with annual revenues exceeding €6 million;
Entities included in VAT groups;
Entities registered in the REDEME system for monthly VAT declarations.

Other businesses and professionals can also voluntarily opt into the SII.

SII technical requirements

The SII focuses primarily on the obligation to electronically declare information about issued and received invoices, among other data, by submitting electronic VAT records to the AEAT in Spain.

The required VAT records include:

Record of issued invoices
Record of received invoices
Record of investment goods
Record of certain intra-community transactions

Generally, information must be submitted to the relevant tax authority within a maximum of four working days from the issuance or receipt of invoices. While the AEAT provides XML file structures and a specific communication process, the SII, unlike TicketBAI or Verifactu, does not require:

Chaining of records,
Electronic signatures, or
Certification of the management software used for information submission.

Coexistence of SII with Verifactu and TicketBAI

As mentioned earlier, the Spanish tax system is complex, with various regional and national tax authorities, as well as multiple regulations affecting different types of businesses. Thus, Verifactu and TicketBAI will coexist with the SII system.

Crea y Crece Law and e-Invoicing

Law 18/2022, enacted on September 28 and known as the Crea y Crece Law, was designed to promote digitalization, reduce late payments between businesses and professionals, and improve management processes through mandatory e-invoicing, among other measures.

What does the Crea y Crece Law entail?

According to Article 12, companies and freelancers will be required to issue and receive e-Invoices through providers that ensure interconnection between platforms and the e-Invoicing formats specified by the law.

The obligation to issue e-Invoices applies to B2B transactions where both the client and recipient operate in Spain. Businesses must issue e-invoices using software that complies with the law, is registered with the AEAT, and ensures proper connection to the public e-Invoicing solution, where records will be submitted by taxpayers. This requirement will only apply to complete invoices, not simplified ones.

e-Invoicing systems must:

Ensure interconnection between e-Invoicing platforms.
Comply with AEAT-specified formats for issuing complete invoices.
Connect with the AEAT’s public e-Invoicing solution to submit records.

E-invoicing under this law will apply exclusively to complete invoices and is expected to significantly reduce payment delays between businesses. Official requirements are expected to be published in 2025.

e-Invoicing API

Whether your business issues or receives complete invoices from other professionals or companies, or you are a developer of billing, management, or fiscal software, the new Crea y Crece Law affects you and must be implemented mandatorily.

Our SIGN ES API includes e-Invoicing capabilities compliant with the Crea y Crece Law, in addition to Verifactu and TicketBAI functionalities.

SIGN ES: one API for multiple fiscal legislations

An API like SIGN ES is the ideal solution to integrate into existing POS, ERP, or billing software to ensure compliance with Spain’s tax regulations, including Verifactu, TicketBAI, and e-invoicing under the Crea y Crece Law.

What is SIGN ES?

SIGN ES is an API specifically developed to ensure businesses comply with Spanish tax laws, including mandatory e-invoicing. With easy integration, SIGN ES seamlessly adapts to any billing software, such as ERP, POS, or other systems, allowing businesses to comply with tax regulations without significant infrastructure changes.

Benefits of SIGN ES

100% fiscal compliance: ensures all issued invoices meet regulations such as Verifactu, TicketBAI, and the Crea y Crece Law.
Constant updates: your software will always stay up to date with changes made by the AEAT, ensuring protection against potential penalties.
Compliant with multiple regulations: a single integration allows compliance with various fiscal regulations in Spain, simplifying processes for businesses operating across regions.
Simple API integration: we provide clear technical documentation and a testing environment so you can try out the API before signing any contracts.
Expert support: access a specialized team in fiscalization and development to guide you through the implementation process and beyond.

Why choose SIGN ES?

We understand that fiscal compliance can be challenging, especially for businesses needing to update their systems to align with new rules. SIGN ES simplifies this process, providing an effective solution tailored to each business's needs.

If you’re looking for a simple and effective integration to ensure compliance in Spain, our team is ready to help you understand how SIGN ES can transform the way you manage your invoicing.