The Anti-Fraud Law 11/2021 introduces major changes in how retail businesses must handle invoicing. From limiting cash payments to requiring invoicing software that ensures traceability and immutability, this regulation directly affects any business that issues receipts or invoices through a point of sale terminal (POS).
If you’re selling in-store with Shopify POS, it’s essential to ensure your operations are compliant. Fortunately, tools like Comply, specifically designed for this environment, make adapting to the law simple, secure, and frictionless.
What Is the Anti-Fraud Law?
Law 11/2021 on measures to prevent and combat tax fraud aims to eliminate opaque accounting practices and strengthen control over sales and invoicing operations. It affects all actors in the economic system—from sole traders to large corporations, including software developers and POS solution providers.
There are two key aspects of the law that apply directly to point-of-sale systems:
Restrictions on cash payments
Strict control over invoicing software, explicitly banning any tool that enables the modification or deletion of transactions (so-called “dual-use” software)
What Does This Mean for Businesses Using Shopify POS?
Businesses operating with a POS like Shopify POS are required to use invoicing software that:
Ensures the immutability of all recorded transactions
Generates a verifiable record for each operation
Maintains full traceability of all sales activity
Prevents any manipulation of data after issuance
Comply was built precisely for this purpose: to enable physical retail stores using Shopify POS to issue legally valid invoices in full compliance with the Anti-Fraud Law, including current requirements and those that will take effect under Verifactu in 2026.
What Technical Requirements Does the Law Impose?
Dual-use software is prohibited: It is expressly forbidden to use any system that allows invoices to be deleted, modified, or overwritten without trace.
Mandatory data retention for a minimum of 4 years in a format accessible and readable by the AEAT.
Complete traceability for every transaction, including digital signatures, sequential numbering, and audit trails.
Issuing duplicate or parallel invoices to hide revenue is forbidden.
Comply meets all of these requirements and was developed according to the technical specifications laid out by the Spanish Tax Agency. Its integration with Shopify POS guarantees that invoices issued at the POS are legally protected and audit-ready at all times.
What Is Verifactu and How Is It Related to the Anti-Fraud Law?
Verifactu is the technical system developed by the AEAT as a regulatory implementation of the Anti-Fraud Law. It defines specific requirements that invoicing software must meet, including:
Immutable, chained invoice sequencing
QR codes and other unique identifiers embedded in each invoice
Real-time submission of invoicing records to the tax authorities
Verifactu will become mandatory for point-of-sale systems as follows:
January 1, 2026 for companies subject to Corporate Income Tax
July 1, 2026 for sole traders and SMEs
Comply is already Verifactu-ready, enabling businesses to adapt in advance—without waiting for the deadline.
What Happens If You Don’t Comply?
Non-compliance with the Anti-Fraud Law can lead to significant penalties for both businesses and software providers:
Up to €50,000 per fiscal year for using non-compliant software
€1,000 per transaction if altered or not properly recorded
Additional fines for repeated violations or failure to cooperate with inspections
Compliance is not optional, and the sooner your POS invoicing system is updated, the better protected your business will be.
How Does Comply Help You Comply with the Anti-Fraud Law?
Comply is developed by DAP Consulting SL specifically for merchants using Shopify POS. Thanks to this specialized focus, you can continue selling in-store as usual—while Comply ensures you stay compliant:
Invoices issued with full traceability
Sequential numbering, digital chaining, and immutable records
Structured data exports for audits or tax filings
Full readiness for Verifactu and compatibility with SII and TicketBAI