If there is one aspect of Law 10/2025 that will directly impact the day-to-day operations of customer service teams in the financial sector, it is the new framework for complaint resolution deadlines. The maximum response time is reduced from two months to one. Half the time to resolve complaints, while maintaining the same quality standards in responses and with the obligation to document everything. For many institutions, this is not a minor adjustment: it is a complete process redesign.
However, there are important nuances. The Customer Service Law (Ley SAC) does not establish a single deadline for all complaints in the financial sector. Instead, it introduces a distinction by type of service, requiring each complaint to be classified from the very moment it is registered.
The New Deadline Framework
Once the law comes into force, financial institutions must manage complaints according to the following differentiated structure:
• General complaints: maximum of 1 month from the formal submission of the complaint until the reasoned response is communicated to the customer. This specific deadline applies to the financial sector under sector-specific regulations, which take precedence over the general Customer Service Law. For all other sectors, the general deadline remains 15 business days.
• Payment services (payments, transfers, cards): maximum of 15 days. The shorter deadline already established under PSD2 remains in place. In this case, sector-specific regulation is stricter, not more flexible.
Previous regulation treated complaints in a generic manner, with a single two-month deadline for all cases. The Customer Service Law breaks this uniformity and introduces the need to classify and categorize each complaint according to the nature of the service involved. This has a direct impact on management systems, workflows, and agent training.
Why Accurate Classification from the First Contact Is Essential
If the deadline for a complaint related to a bank transfer is 15 days, while a complaint regarding a life insurance product allows one month, the system must identify the type of complaint from the very first registration and activate the correct deadline counter. Without this automatic or guided classification, the risk of non-compliance increases significantly, especially during periods of high volume.
This requires reviewing intake forms, categorization systems, escalation workflows, and automatic alerts for the teams responsible for each type of complaint. An issue related to an unauthorized card charge cannot be managed under the same deadline structure as a complaint concerning mortgage conditions.
Correct classification from the start provides another key advantage: prioritization. In high-volume environments, understanding that some complaints must be resolved within 15 days while others allow one month enables a far more efficient distribution of workload.
The Real Impact on Internal Processes
Cutting resolution times in half without reducing response quality requires identifying the real operational bottlenecks. Based on Consulting C3’s experience working with financial institutions, the most common issues are:
• The number of internal escalations required to resolve a complaint, as each escalation adds delays.
• Dependence on other departments (product, risk, legal) to obtain the necessary information. If these departments do not operate under internal SLAs aligned with the new regulatory deadline, the Customer Service department will not be able to comply.
• Agents’ ability to draft high-quality reasoned responses without always depending on higher-level validation.
• Internal approval times for responses, especially in complex or high-value complaints.
Evidence and Documentation: What Regulators Will Require
Compliance alone is not enough: institutions must also be able to prove it. Companies must maintain clear records of the exact time each complaint was received, its classification, the applicable deadline, and the date on which the response was communicated. This documentary traceability is what protects institutions during inspections or in the event of direct customer claims.
One particularly sensitive point is the starting moment of the deadline. The law establishes that the countdown begins from the formal submission of the complaint. Does the customer receive an automatic acknowledgment with date and time? Does that acknowledgment specify the applicable maximum response time? These are questions that must already be answered before the regulation comes into force.
What Financial Institutions Should Be Doing Now
• Review the current complaint management process and identify where the greatest delays occur.
• Implement an automatic or guided complaint classification system by service type, activating the corresponding deadline from the first registration.
• Align the internal SLAs of support departments (product, risk, legal) with the new one-month regulatory deadline.
• Ensure customers receive an automatic acknowledgment including the start date and maximum response deadline.
• Review alert systems so teams are notified when a complaint is approaching its deadline.
The shift from two months to one is not impossible to manage, but it requires a deliberate redesign of processes. It is not enough to do the same work in less time: it must be done differently.