Billing transparency: what Circular 3/2024 requires
Circular 3/2024 requires retail energy suppliers to itemise every price component on the customer invoice in a format that is comprehensible to a non-expert consumer. The required components are: energy cost (including wholesale market exposure), network access tariffs (peajes), regulatory charges (cargos), applicable taxes (IVA, electricity tax), and the supplier's margin. Generic line items such as «energy supply cost» are not sufficient.
The practical challenge for mid-size retailers is systems integration: billing software must be updated to pull each cost component separately and render them in the prescribed format. Retailers operating across multiple autonomous communities face additional complexity, as some regions have local energy taxes that must also be itemised separately.
Spain's collective self-consumption framework — which enables multiple consumers to share the output of a single photovoltaic or wind installation — now has clear regulatory architecture. Installations exceeding 100 kW that serve five or more consumers must: register in the CNMC's specific self-consumption registry before operation begins; submit monthly production and distribution data to the CNMC; appoint a responsible party (persona responsable) for regulatory compliance; and notify changes in consumer composition within 30 days.
For property managers and homeowners' associations (administradores de fincas), this is particularly relevant: residential communities that installed shared solar panels in 2023–2024 may not yet be registered in the CNMC system, and face a compliance deadline. IgeraFincas can help property managers track these obligations across their entire portfolio of communities.
ESG reporting: new obligations for energy sector companies
Retail energy suppliers with more than 250 employees or annual turnover exceeding €50 million are now required to include Scope 1, 2 and 3 greenhouse gas emissions data in their annual sustainability report. The CNMC can request external audit verification of these figures. The first annual reports subject to this requirement cover the 2025 financial year, to be published in 2026.
Scope 3 reporting is the most complex element — it requires tracking emissions throughout the supply chain, from upstream energy procurement to downstream customer consumption. IgeraLegal can help energy companies maintain the documentary evidence trail for Scope 3 calculations, ensuring audit-readiness without manual document management overhead.
How AI helps energy companies manage CNMC compliance
Energy regulation is vast, changes frequently, and varies depending on company type, installed technology, and autonomous community. No single compliance officer can hold all of it in their head. A RAG-powered AI system trained on CNMC circulars can.
1
Instant regulatory answers with citations
Ask "What must be itemised on an invoice for a PVPC customer?" and receive the answer citing the exact article of Circular 3/2024 — not a generic summary.
2
Regulatory change alerts
When the CNMC publishes a new circular or resolution, IgeraLegal automatically identifies which of your current contracts or procedures are affected and flags them for review.
3
Audit trail generation
Every regulatory query and the document cited is logged with a timestamp. When a CNMC auditor requests documentation, you have a complete, searchable compliance history.
4
ESG document management
IgeraLegal organises all ESG supporting documentation — supplier certificates, consumption data, emissions calculations — and generates the checklist for external audit preparation.
Results for a mid-sized energy retailer using IgeraLegal
- −60% time on internal regulatory queries
- −90% risk of applying a superseded regulation
- 100% documentary traceability in CNMC audits
- ESG report preparation time reduced from 6 weeks to 2 weeks
Is your energy compliance team managing CNMC obligations manually?
IgeraLegal centralises all CNMC documentation with AI. Instant answers, regulatory change alerts, and full audit trails for every obligation.
Explore IgeraLegal for Energy
Common compliance errors — and how to avoid them
The most frequent CNMC compliance failures fall into four categories: applying a superseded circular (e.g. using Circular 2/2020 when 3/2024 already applies to billing); failing to register supply contracts signed before January 2026 by the June 2026 deadline; operating self-consumption installations without CNMC registration; and submitting ESG data without the supporting documentary evidence required for external audit.
All four errors share a common root cause: relying on individual knowledge rather than a centralised, up-to-date regulatory document system. When a compliance officer leaves the organisation, or when a circular is published and no one has the bandwidth to update internal procedures, the gap between the company's practices and the current regulatory requirement widens silently — until an audit or inspection makes it visible.
Frequently Asked Questions
Does the CNMC framework apply to foreign energy companies operating in Spain?
Yes. Any company supplying energy to customers in Spain, distributing energy through Spanish networks, or operating self-consumption installations connected to the Spanish grid is subject to CNMC regulation regardless of where the company is headquartered. This includes subsidiaries of European energy groups operating in the Spanish market.
What is the difference between CNMC and REE (Red Eléctrica de España)?
REE (now Redeia) is the national transmission system operator — it physically manages the high-voltage grid and system balancing. The CNMC is the independent regulator that sets the rules, supervises compliance, and imposes sanctions. Companies report to both: to REE for grid operations and to the CNMC for market conduct and regulatory compliance.
How does the collective self-consumption registry work in practice?
The CNMC operates an online registry where self-consumption communities must submit technical data (installation capacity, connection point, technology type), consumer composition (number and type of consumers, distribution coefficients), and monthly production data. Changes to consumer composition — e.g. a flat owner selling their property — must be reported within 30 days. IgeraFincas helps property managers track these obligations across their portfolio.
Is ESG reporting under CNMC linked to the CSRD directive?
The CNMC's ESG reporting requirement is sector-specific and predates full CSRD transposition in Spain. It aligns broadly with CSRD scope but is narrower: it focuses on emissions data and renewable energy mix. Companies in scope for both CNMC energy ESG reporting and CSRD should align their data collection processes to avoid duplicating effort — IgeraLegal supports both frameworks from a single document management system.
What records does the CNMC require companies to maintain?
Record-keeping requirements vary by obligation type. Supply contracts must be retained for at least 5 years after termination. Billing records must be kept for 3 years. Self-consumption production data must be retained and available for CNMC inspection for the duration of the installation's operating licence. ESG supporting documentation must be available for at least 3 years following publication of the annual report.
How quickly can IgeraLegal be deployed for a mid-size energy retailer?
A standard deployment for an energy retailer — indexing CNMC circulars, RITE resolutions, internal procedures and contract templates — takes 5–10 working days from document submission to a live, queryable system. Channel integrations (intranet, SharePoint, CRM) add 1–2 weeks. Full deployment including user training is typically completed within 4 weeks.
Article by Igera Solutions editorial team. Updated June 2026. Products: IgeraLegal — AI-powered regulatory compliance for law firms, energy companies, and regulated industries. Also: IgeraFincas for property management and self-consumption compliance tracking.
