The Immediate Supply of Information (SII) is an electronic VAT management system developed by the Spanish Tax Agency (AEAT) that applies to large enterprises, VAT groups, and companies enrolled in the REDEME scheme. Although its primary purpose is to enable near real-time communication of invoice ledgers, not all software must connect directly to the AEAT to meet SII requirements.
Comply, as a solution built specifically for Shopify POS, offers a practical and effective approach for point-of-sale environments subject to the SII. It structures invoice records in the legally required format, preserves sequential numbering, and enables easy export for review or submission by your tax advisor—without requiring direct integration with the AEAT.
What Is the SII and How Does It Affect Retailers?
In effect since July 2017, the SII requires certain taxpayers to submit their VAT ledgers electronically and almost in real time. Issued and received invoices must be reported within four business days, with the goal of improving fiscal control and reducing tax fraud.
Who is required to comply?
Companies with annual revenue exceeding €6 million
Entities registered in the REDEME (Monthly VAT Refund Registry)
VAT groups
For these cases, SII compliance requires rigorous, structured invoice management—even at the point of sale. That’s where Comply becomes a key ally.
What Does Comply Offer for SII Compliance via Shopify POS?
While Comply does not directly transmit invoice records to the AEAT under the SII framework, it does provide everything necessary to ensure your company (or your accountant) can report the data accurately and on time.
Specifically, Comply enables:
Sequential invoice numbering: Every invoice issued in Shopify POS is recorded with a unique and sequential identifier, as required by SII.
Structured invoice record generation: Comply captures all essential data (taxable base, VAT rate, customer NIF, date, etc.) in a format aligned with the AEAT’s requirements.
Easy export: All invoice records can be downloaded as a structured file ready for submission, either manually or via your accounting software.
This means that even without automatic AEAT integration, your day-to-day POS operations remain fully compatible with SII obligations.
Benefits of Using Comply for SII in Shopify POS
Operational simplicity: No need to alter your in-store workflow or adopt new systems—everything starts within Shopify POS.
Fewer errors: Invoices are recorded automatically, reducing the risk of duplication or data entry mistakes.
Accountant-friendly: The CSV file can be directly imported into accounting software connected to the SII system.
No technical overhead: Comply meets all technical standards while allowing the user or their advisor to handle submission externally.
What Doesn’t Comply Do Under the SII Framework?
To clarify, Comply is not designed to connect directly to the AEAT for SII. This means:
It does not perform real-time or direct transmission of VAT ledgers.
It does not validate records with the tax authority (this is the accountant’s responsibility).
It is not a replacement for accounting software that communicates with the SII system.
Instead, Comply serves as a structured data collection tool that aligns with SII compliance, making it easier to meet obligations downstream.
Why Is Comply an Ideal Solution for POS Under the SII?
Many retailers using Shopify POS are subject to the SII due to their group structure or high annual turnover. For those businesses, Comply:
Seamlessly integrates with the Shopify POS environment
Fulfills AEAT’s technical standards for numbering, traceability, and record structure
Allows effortless data export to your accounting team or advisor
Avoids costly or complex integrations that may not make sense for in-store volume
Conclusion
If you run your physical store with Shopify POS and must comply with the Immediate Supply of Information (SII), Comply provides a practical, low-friction solution. You don’t need an additional system or direct technical connection—just configure your fiscal data correctly, maintain your usual POS workflow, and export your records when needed.