Renewable Energy Communities (CER - Comunità Energetiche Rinnovabili) constituted under D.Lgs. 199/2021 are liable persons for electricity excise purposes when they produce, share or supply energy via the grid. From 1 January 2026, the CER - as a collective legal entity - must submit the AD-1 declaration semi-annually under Art. 53 TUA (D.Lgs. 43/2025): the first deadline is 30 September 2026for semester H1 (January-June 2026). The declarant is the CER's legal representative registered with ADM, not the individual producer or consumer members. Failure to file is punishable by a penalty of 100% to 200% of the tax due, minimum €500.
What is a Renewable Energy Community for excise purposes
A CER is an independent legal entity - an association, cooperative, third-sector body or not-for-profit company - that aggregates renewable energy producers and consumers within a geographic boundary defined by GSE regulations. For excise purposes, the CER is treated as a single operator: the CER itself - not its members - holds the ADM licence or authorisation and files the AD-1 declaration. Each member remains responsible for their own final consumption, but the declaration of energy produced and shared is the CER's responsibility as an entity.
Who is the liable person in a CER
The liable person is the CER as a legal entity, under Art. 53, c.1 or c.3 TUA depending on the configuration:
- Art. 53, c.1 TUA (operating licence) - if the CER supplies energy to third parties or the grid outside collective self-consumption
- Art. 53, c.3 TUA (notification) - if the CER produces renewable energy with capacity between 20 kW and 200 kW with grid injection, without a full licence
- Art. 53, c.5 TUA (own-use authorisation) - if the energy produced is collectively consumed by the members without supply to third parties
The signatory of the declaration is the CER's legal representative. Where the CER manages both collective self-consumption and energy supplied to third parties, it may be classified as a consumer-seller and required to complete additional quadri (sections).
Which AD-1 quadri must a CER complete
The mandatory quadri (sections) depend on the CER's technical configuration:
| CER configuration | Required AD-1 quadri |
|---|---|
| Collective self-consumption only | Quadro A, Quadro C |
| With grid supply to third parties | Quadro A, Quadro B, Quadro C |
| With BESS (battery storage system) | Quadro A, Quadro B (if supply), Quadro C, Quadro E |
| With integrated RIU | Quadro A, Quadro B, Quadro C, Quadro H |
Quadro A collects identification data and aggregate quantities. Quadro C covers energy produced from renewable sources. Quadro B is required for supply to third parties. Quadro E records BESS charge and discharge data for the semester. Quadro H is specific to RIU (internal distribution networks).
2026 semi-annual deadlines
| Semester | Reference period | Filing deadline |
|---|---|---|
| H1 2026 | 1 January - 30 June 2026 | 30 September 2026 |
| H2 2026 | 1 July - 31 December 2026 | 31 March 2027 |
The first meter reading relevant for the H1 declaration must be taken on 30 June 2026. The H2 closing reading must be taken on 31 December 2026.
CER with BESS or mixed use
CERs equipped with battery storage systems (BESS) must separately track energy charged into the battery and energy discharged, because the two quantities affect the excise calculation differently. Energy discharged from the BESS and supplied to final consumers is subject to excise; energy directly self-consumed by the CER's members is treated as collective self-consumption. Quadro E of the AD-1 declaration is dedicated to recording these flows during the semester.
Mixed use - part of the energy produced self-consumed, part supplied - requires separate accounting by intended use. A CER without a separate metering system for different uses risks being unable to correctly complete the required quadri.
Difference between CER and RIU (Internal Distribution Networks)
A CER can aggregate plants and consumption points that are physically distant from each other, connected via the public distribution grid. An RIU (Rete Interna d'Utenza) is a private network connecting multiple injection and withdrawal points within a physically delimited perimeter (e.g., an industrial site, a complex).
For ADM purposes the distinction matters: RIUs complete Quadro H, CERs without RIU do not. A CER that also manages an internal RIU (e.g., condominiums with a shared private network) must complete both and declare the two perimeters separately.
Checklist for the CER manager
- Verify the CER has an ADM licence or authorisation issued to the CER as a legal entity (not to individual members)
- Identify the technical configuration: collective self-consumption only, grid supply, BESS, RIU
- Determine the mandatory AD-1 quadri based on the configuration (table above)
- Set up monthly metering of kWh shared and supplied for each measurement point (required for monthly payments from 2026)
- Collect meter readings on 30 June 2026 to close H1 semester data
- Calculate and provide the surety bond (15% of estimated annual excise, DM 10 March 2026)
- File the AD-1 H1 declaration by 30 September 2026
Legal sources
- D.Lgs. 14 March 2025, n. 43 - Art. 53 TUA (liable persons and declarant figures)
- ADM Circular 32/2025 - new intended uses, AD-1 quadri instructions for CERs
- DM 10 March 2026 - semi-annual declaration, monthly payments, 15% bond
- D.Lgs. 8 November 2021, n. 199 - establishment and regulation of CERs in Italy
- D.Lgs. 504/1995 (TUA), Arts. 52-54 - electricity excise, legal basis
Deklara manages CER declaration obligations: from the plant registration to the semi-annual AD-1 declaration, with support for all 8 declarant figures under the TUA.