Law 10/2025 on Customer Service sets a clear countdown for all financial institutions: they have until December 28, 2026, to adapt their operations. One of the requirements raising the most questions among operations teams is the new waiting time limit for inbound customer service calls, as it directly impacts workforce planning, technology, and the service model itself.
During the executive webinar organized by Consulting C3 together with the Spanish Association of Customer Relationship Experts (AERC), this was the topic that generated the highest number of questions. And for good reason: the nuances that separate compliance from non-compliance are significant.
What does the law say?
The amendment to Law 44/2002 is clear: 95% of inbound Customer Service (SAC) calls must be answered within a maximum of 3 minutes. This threshold is measured on an annual basis, meaning that not every individual call is required to meet the target, but the overall yearly average must comply.
Achieving this 95% target has major operational implications. Those managing customer service centers know that reaching this level effectively means maintaining an abandonment rate between 1% and 2%, which requires a complete review of workforce management and capacity planning models.
When does the waiting time start counting?
This detail directly affects how measurement systems must be configured. The law distinguishes between two scenarios:
• If the customer calls the Customer Service department directly without going through any automated system, the timer starts from the very first second of the call.
• If the customer first accesses an IVR or any other self-service system, the timer starts the moment the customer explicitly requests to speak with a human agent.
This second point is especially relevant for institutions already operating IVR systems: the clock does not start when the customer dials the number, but when they request human assistance. The contact center platform must accurately and audibly register that moment, as an approximate estimation will not be sufficient.
Callback: a safety valve with conditions
The law allows institutions to offer a callback service when waiting times are expected to exceed the limit. However, offering a callback does not exempt the institution from complying with the KPI. The metric still measures the actual waiting time, regardless of whether the customer accepted a deferred call.
Callback cannot become a systematic workaround. If an institution relies on it massively and takes hours — or even days — to return calls, it creates clear evidence of non-compliance that can easily be detected during an audit. The law requires real responsiveness and the ability to prove it with data. The UNE Committee is currently working on clarifying whether a callback offered before exceeding the threshold counts as KPI compliance.
Example: if service hours end at 10:00 PM and a customer accepts a callback at 9:55 PM, that call cannot simply be postponed until the following day. Responsiveness remains an enforceable criterion even if it is not quantified with the same level of detail as the main KPI.
Measurement, logging, and reporting obligations
Complying with the KPI is not enough: institutions must also be able to demonstrate compliance. Financial entities are required to maintain systematic KPI records available for regulatory audit at any time. This involves periodic reporting with data broken down by time slot, channel, and service type, properly stored and preserved.
The calculation is annual, but supervision may occur at any moment. And oversight will not only come from regulators: customers who believe they were not assisted within the required timeframe will be able to file complaints with Consumer Protection Authorities starting January 1, 2027.
What should your institution be doing right now?
• Measure current waiting times and calculate how far you are from the 95% within 3 minutes threshold. Without real data, there is no baseline.
• Review telephone service capacity planning: shifts, demand peaks, and agent-to-call volume ratios.
• Assess the role of callback within the customer service model. If you already use it, make sure response times and records are properly documented.
• Confirm that the technology platform accurately detects and logs the exact moment a customer requests human assistance through the IVR.
• Prepare regulatory reporting processes: format, frequency, and data custody chain.
Consulting C3 and MST Holding have been working for months with financial institutions on diagnostics and adaptation plans for the SAC Law. As members of the UNE Committee, we provide our clients with the most up-to-date interpretation of every regulatory requirement.