Electricity and gas in Spain are liberalized markets regulated by the CNMC: every supply point has a unique **CUPS** code (Código Universal del Punto de Suministro) that identifies the connection regardless of which company supplies it, and consumers are free to choose and switch their **comercializadora** (retail energy supplier) at no cost. Water is different: it is not a liberalized national market but is contracted directly with the local municipal or regional water utility (e.g., Canal de Isabel II in the Madrid region), since water supply is managed at the municipal/regional level rather than nationally.
New property owners need the CUPS code to set up or transfer electricity and gas accounts, and confusing the liberalized energy market with the municipal water system is a common source of delay — water has its own separate application process with its own local provider, documentation, and fees.
Key Facts
The **CUPS** is a unique, permanent identifier for each electricity or gas supply point in Spain; it does not change even when the customer switches comercializadora. It starts with "ES" (country code) followed by digits identifying the distribution company (which is fixed by location and cannot be chosen).
Electricity and gas are handled by two distinct types of companies: **distribuidoras** (grid/pipeline operators, fixed by location, not chosen by the consumer) and **comercializadoras** (retail suppliers, freely chosen and freely switchable).
The CNMC maintains the **SIPS** (Sistema de Información de Puntos de Suministro), the regulated database of technical, consumption, and commercial data tied to each CUPS, which comercializadoras use to process supply and switching requests.
Switching electricity comercializadora is free of charge; CNMC guidance states consumers have the right to complete a switch within a **maximum of 10 business days** from contract formalization (extendable by up to 5 additional business days for complex field operations).
Switching gas comercializadora is also free; CNMC guidance gives a **maximum of 3 weeks** for the changeover, though this can be adjusted to align with actual meter readings.
A comercializadora will typically request the CUPS code, the desired tariff, ID/NIF, contact details, and bank details for direct debit when setting up or switching a contract.
Water supply is **not** part of the CNMC-regulated liberalized market — it is contracted with the applicable municipal or regional public water company. As an example, in the Madrid region this is **Canal de Isabel II**, which requires the property deed (or purchase contract) and ID to open a new water account ("alta de suministro") or transfer an existing one into a new owner's name ("cambio de titularidad").
Steps
1. Find the property's CUPS code — The CUPS is shown on the previous owner's electricity/gas bill, or can be requested from the distribuidora or an incoming comercializadora once the buyer has ID/NIE and proof of the address.
2. Choose a comercializadora for electricity (and gas, if applicable) — Compare offers among the available comercializadoras — the CNMC publishes consumer guidance and a market comparator to support this — and provide the CUPS, ID/NIF, and bank details to contract or switch supply.
3. Set up water with the local/regional water utility — Contact the municipal or regional water provider serving the property (this varies by location — Canal de Isabel II for the Madrid region is one example) and apply for a new connection ("alta") or a change of ownership ("cambio de titularidad") using the property deed and ID.
4. Confirm activation and update billing details — Once accounts are active, confirm meter readings and set up direct debit if desired.
Timelines
Electricity supplier switch: up to 10 business days (up to 15 for complex cases), per CNMC.
Gas supplier switch: up to 3 weeks, per CNMC.
Water — example from Canal de Isabel II (Madrid region): new supply activation ("alta") around 3 business days if no new physical connection is needed, up to 10 business days if a new connection to the general network is required; change of ownership ("cambio de titularidad") activated in around 3 business days once signed. Note: this is one regional utility's own published figures and will differ by municipality/region.
Required Documents
ID/NIE
Property deed (escritura) or purchase contract
CUPS code (for electricity/gas)
Bank account details for direct debit (typical requirement, not universally mandatory)
Common Mistakes
Assuming water works the same way as electricity/gas (a single national liberalized market) — water is a separate, locally-contracted utility.
Not transferring water ownership promptly after a purchase: under general municipal water regulation practice (e.g., Canal de Isabel II cites Decreto 2922/1975 for Madrid), failing to update the account holder within the required window can result in the utility applying penalty surcharge rates.
Losing track of the CUPS code — it is required by any comercializadora to process an alta or a switch, and not having it on hand can delay setup.
Not realizing electricity and gas distribuidoras (the grid operator) are fixed by location and cannot be shopped around, even though the comercializadora (retailer) can.