The Immediate Supply of Information (Suministro Inmediato de Información – SII) is an electronic system developed by the Spanish Tax Agency (AEAT) for the digital management of Value Added Tax (VAT). This system allows businesses to fulfill their VAT-related tax obligations more efficiently and in real time.

Key Features of the SII

• Electronic Management System: It enables the immediate sending and receiving of VAT-related information through the Internet.
• Digitalization of Registration Books: Facilitates the electronic submission of VAT Registration Books, including issued invoices, received invoices, intra-community operations, and investment goods.
• Real-Time Communication: Taxpayers must provide information about their invoices within a very short timeframe, typically within four calendar days from the issuance of the document.

Objectives of the SII

1. Simplification of Procedures: Streamlines VAT management and reduces formal obligations for businesses.
2. Improved Tax Control: Allows the Tax Agency to have updated information, facilitating the fight against tax fraud.
3. Assistance to Taxpayers: Provides real-time tax data and extends the deadline for submitting declarations.

Entities Required to Use the SII

The system is mandatory for:

• Large companies (those with a turnover exceeding 6 million euros)
• Companies registered in VAT groups
• Companies registered in the Monthly VAT Refund Regime (REDEME)
• Companies that voluntarily choose to adopt the system

Advantages of the SII

• Simplification of tax processes
• Reduction in certain reporting obligations (such as submitting forms 347, 340, and 390)
• Extension of the deadline for filing VAT returns (from 20 to 30 days)
• Enhanced control and traceability of commercial operations

In summary, the SII represents a significant advancement in the digitalization of tax processes in Spain, offering benefits for both tax authorities and taxpayers in terms of efficiency, control, and simplification of procedures.