On December 27, 2025, Law 10/2025 on Customer Care Services (SAC Law) was published in the Official State Gazette (BOE). This law does not redefine how customer services should be organized. It redefines something else: who assumes the risk when there is a dispute. The answer is clear: the company.
| Benefits of an Orchestrated Omnichannel Solution | Description of the Impact on the Customer | Key Business Benefit |
|---|---|---|
| Unified and Consistent Customer Experience (CX) | Customers receive the same tone, design, and quality of information regardless of whether they open an email, an SMS, a WhatsApp message, or a physical letter. | Increased satisfaction (NPS) and customer loyalty. |
| Optimization of the channel mix (efficiency and cost) | Intelligent use of more cost-effective digital channels (email/SMS) as a first step, resorting to physical mail only if there is no response or when required by law. | Drastic reduction in operational costs for postage and printing. |
| Higher delivery rate and effective response | If a channel fails or is ignored, the system automatically activates an alternative or backup channel, ensuring that critical communications are delivered. | Maximizing impact and reducing processing times (e.g., collections). |
| Traceability and Integrated History | The entire sequence of submissions and responses (both physical and digital) is recorded in a single timeline accessible to customer service teams. | Simplified regulatory compliance (accountability) and improved support. |
| Personalization Based on the User’s Actual Preferences | The system learns and interacts through the customer’s preferred channel (e.g., WhatsApp for quick alerts, paper for lengthy contracts). | Improved engagement and lower unsubscribe rates. |
Companies must demonstrate that they have acted in accordance with the law.
The rule introduces a silent but profound change. Faced with a complaint, an inspection or a consumer proceeding, It is no longer enough to state that one acted in accordance with the law. It must be proven. With objective evidence. With full traceability. With lasting support. And, above all, with the capacity to resist third parties. If it cannot be proven, the substance of the matter loses relevance.
In addition, if the company does not comply with this evidentiary capacity before December 28, 2026, it may face heavy fines and a loss of credibility with its customers that is difficult to quantify.
The Law does not discriminate by channel. It makes no difference whether the interaction takes place by telephone, e-mail, web, instant messaging or in person. The legislator did not want to regulate means, but legal consequences. Each query, complaint, claim or incident becomes a potentially probative fact. And as such, it must leave a verifiable record of its content, date and time. It must generate a supporting document for the consumer. And it must be kept in its entirety until the complete resolution of the file.
The pain for companies is clear. The burden of proof is on the company. It is not a doctrinal interpretation or a self-serving reading. It is an express obligation. From now on, when something is wrong, it is not discussed who is right. It is examined who can prove it.
Sectors affected
The impact is immediate in sectors with high regulatory and litigation exposure. Telecommunications, energy, water, transportation and postal services. already operate under constant supervision. But the scope is not limited to traditionally regulated sectors. The Act also applies to large B2C companies by volume, regardless of their activity. In banking and insurance, sector-specific regulations continue to take precedence, but the standard of proof is not relaxed. It is raised. The logic is the same: more requirements, more documentation, more pressure in the pre-litigation phase.
Outsourcing the customer service does not alter this scenario. Subcontracting does not shift liability. The risk remains with the main operator. The file remains yours. And so does the proof.
| Communication Channel | Key Features | Recommended Use Case |
|---|---|---|
| Certified Email | Low cost, allows you to attach large files, provides full tracking of delivery and opening, and is legally valid. | Contractual notifications, sending policies, and changes to terms and conditions. |
| Certified SMS | Highest open rate (98%), immediate delivery to mobile devices, ideal for short, urgent messages requiring legal proof. | Non-payment alerts, security OTP codes, urgent due date reminders. |
| WhatsApp Business | High interactivity, two-way communication, a user-friendly environment, supports multimedia content and quick-reply buttons. | Customer service, claims management, appointment confirmations, and loyalty campaigns. |
| Burofax / Certified Mail | Traditional channel, absolute legal certainty, required by law for certain proceedings, physical delivery upon signature. | Debt collection through enforcement proceedings, formal notices of contract termination. |
One of the most frequent errors
Many organizations believe they are compliant because “everything is recorded in the system”. A CRM. An internal ticket. An email history. A stored recording. That approach is no longer sufficient.
A CRM is not proof. An ordinary email is not proof. A recording without certification is not proof either. They are internal records, with no technical guarantees of integrity or unalterability against third parties. They work as long as they are not challenged. The moment they are challenged, their value weakens. In consumer proceedings, they fall easily. In arbitration, too. In court, even more so.
The SAC Act does not require documentary efficiency. It requires defensible evidence. Solving this problem does not involve turning companies into digital testing specialists. It involves assuming that testing is part of the compliance infrastructure. And that infrastructure already exists in the ecosystem of trusted services.
| Type of Certified Fax / Postcard | Features and Legal Evidence | Recommended Use Case |
|---|---|---|
| Premium Burofax (Paper) | Urgent physical delivery requiring the recipient’s signature. Includes a Certificate of Contents (proof of what was sent) and a Return Receipt (proof of delivery). Evidence is retained for 5 years. | Debt claims, termination of lease agreements, dismissals, or prior legal notices. |
| Electronic Certified Fax | Immediate notification via electronic means (email/certified SMS) that requires the recipient’s electronic signature to access the content. Generates a record of evidence with an iDAS timestamp. | Agile corporate communications that require maximum legal certainty but at a lower cost than physical solutions. |
| Premium Certified Mail | Physical delivery requiring a signature, with detailed tracking of the shipment’s status. It serves as legal proof of delivery, but does not provide conclusive proof of the envelope’s contents. | Sending credit cards, official welcome materials, or regulated informational notices. |
The role of MailComms Group
This is where MailComms Group is positioned, as a trusted service provider qualified in certified electronic delivery and soon in signature and seal preservation (QPRES) in compliance with eIDAS. Not as a service channel provider, but as an expert in personalized omnichannel communication and provider of evidence with legal value.
Certified electronic notifications provide reliable proof that a communication was sent, made available, received, or attempted to be sent, with its content intact and time-stamped. Claims resolutions. Reasoned responses. Contractual notices. Communications relevant to the case file. Certified email, certified SMS, certified WhatsApp, or online burofax meet the requirement for proof in a durable medium and drastically reduce disputes over evidence.
The law is not limited to individual communications. Many disclosure obligations are fulfilled through websites, customer portals, or private areas. In such cases, the certification of web publications makes it possible to verify what information was available, when it was available, and under what conditions. It is not about archiving the website. It is about being able to prove its content when it is no longer readily accessible.
QPRES: keeping the proof
QPRES (Qualified Preservation Service) is the qualified preservation service for electronic signatures and seals regulated by the eIDAS Regulation, which ensures that evidence already generated retains its evidentiary value over time, even when the original certificates expire or cryptographic algorithms become less secure.
In this context, QPRES fulfills a precise and often misunderstood function. It is neither a general electronic archiving service nor a document preservation service with independent legal effects. Its value lies in the qualified preservation of evidence already generated. Time stamps and electronic signatures, proof of delivery and receipt. QPRES ensures that this evidence remains intact, accessible and verifiable throughout the life cycle of the file, even when the conflict is no longer operational, but legal.
Does not add new effects. It prevents existing ones from being degraded. The requirement of motivation and consistency in the resolutions adds an additional layer. It is not enough to respond. It must be possible to prove who decided, when they decided and with what content. The electronic signature and time stamping close that point. They do not improve the care process. They shield its outcome from third parties.
The real change is conceptual
The change that many organizations have not yet embraced is conceptual. This is not about customer experience. It’s about legal cost. Every claim without solid evidence today is a weakness tomorrow. Every poorly documented file is unnecessary exposure. SAC 10/2025 does not sanction poor care, it sanctions the failure to demonstrate compliant care.
The standard is already in force and the adaptation period is running (until December 28, 2026). The evidentiary standard has already changed, so companies that understand now that the problem is not to communicate, but to prove, will gain margin. The others will understand this when the discussion ceases to be operational and becomes legal.
MailComms Group is not a substitute for customer service. It allows you to prove that you delivered. And from now on, that difference matters.
Frequently Asked Questions
What is the SAC Act, and what does it require companies to do?
Law 10/2025 on Customer Service (SAC Law), published in the Official State Gazette (BOE) on December 27, 2025, introduces a fundamental change: in the event of a complaint, inspection, or consumer proceeding, companies can no longer simply claim that they acted in accordance with the law—they must prove it. This requires having objective evidence, with full traceability and permanent storage, for every communication, resolution, and incident generated by the customer service department. The deadline for compliance is December 28, 2026.
Which sectors are affected by the SAC Act?
The SAC Act applies directly to telecommunications, energy, water, transportation, and postal services. It also applies to large B2C companies based on volume, regardless of their sector. In banking and insurance, sector-specific regulations continue to take precedence, but the standard of proof is not relaxed—it is raised. Companies that outsource their customer service are not exempt: the burden of proof remains with the primary operator.
Is CRM a valid means of complying with the SAC Act?
Not on their own. A CRM, an internal ticket, a history of ordinary emails, or an uncertified recording are internal records with no technical guarantees of integrity or authenticity vis-à-vis third parties. They are effective as long as they are not challenged; the moment they are contested before consumer protection agencies or in court, their probative value is weakened or disappears. The SAC Law requires defensible evidence: communications certified by a qualified PSCC under eIDAS, with a timestamp and content traceability.
What types of evidence are valid for compliance with the SAC Act?
Valid evidence consists of evidence generated by a Qualified Trust Service Provider (QTSP) under eIDAS: certified email, certified SMS, certified WhatsApp, online registered mail, and certified web publications. All of these methods verify the sending, the full content, the delivery, and the sender’s identity with a qualified time stamp, which gives them probative value vis-à-vis third parties. Internal records (CRM, regular mail, uncertified recordings) do not meet this standard on their own.
What are the penalties for violating the SAC Act?
Law 10/2025 establishes a penalty system for which implementing regulations are still pending. The penalties can be substantial financially, but the most significant impact for B2C companies is the loss of credibility with customers and an increase in pre-litigation disputes: without solid evidence, every complaint becomes a legal liability. The deadline to comply before regulatory pressure increases is December 28, 2026.