A bill that looks wrong or double-charged: how to dispute it

Terms used

• Reclamación — A reclamación is a formal written complaint to a provider or authority.
• Potencia — The potencia is the maximum electrical power you contract, which sets part of your fixed charge.
• Bono social — The bono social is a discount on electricity bills for eligible vulnerable households, with extra protection against cut-offs.
• Junta Arbitral de Consumo — The Junta Arbitral de Consumo is a free consumer arbitration board that settles disputes with businesses that have joined it.
• OMIC — The OMIC is the municipal consumer information office run by many town halls.

Key rules

• Complain first: Send a written complaint to the provider before going to any authority, and keep the reference number.
• Answer time: The provider must answer a written billing complaint within one month.
• Refund limit: For electricity and gas, you can claim an overcharge back, and a supplier can correct a bill, for up to five years.
• Cut-off: A complaint does not stop a cut-off, so keep paying the part you do not dispute.
• Electricity notice: Electricity can be cut only after a written notice, and not until at least 30 days after you receive it.

Start with the provider, in writing

Your first move is a formal complaint (reclamación) to the provider's customer service department (servicio de atención al cliente). Do not start with a regulator or a lawyer.

Use a channel that leaves proof: an online form that gives you a receipt, a certified letter, a burofax, or a written complaint handed in at an office. Phone calls are free, but they leave no record. Always ask for a complaint reference number and keep it. A ready-made complaint letter is below.

Before you write, spend ten minutes finding the cause. Common ones are:

• an estimated meter reading instead of a real one
• the wrong tariff or contracted power (potencia)
• a direct debit taken twice, often after switching supplier
• a charge for a service you never asked for, such as insurance or a maintenance pack
• a discount or the bono social not applied
• a promotional phone price that expired, or fees charged after you cancelled
• a leak or faulty meter, for water

The checklist and documents list below show what to gather. Asking for an itemised invoice is usually the quickest way to see what you are being charged for.

How long the provider has to answer

A provider must answer a written billing complaint within one month. If you get no answer, or a reply that does not fix the problem, you can take it to the next level.

• Electricity and gas: your regional consumer authority, or the consumer arbitration board (Junta Arbitral de Consumo) if the provider has signed up to it.
• Water: the operator's own complaint procedure first, then your town's consumer office (OMIC) or the regional consumer body.
• Phone and internet: the telecoms user office (Oficina de Atención al Usuario de Telecomunicaciones).

Going to court is also possible, but it is a last step.

Time limits for back-billing and refunds

For electricity and gas, the five-year limit applies both ways. A supplier can correct a bill for up to five years, and you can claim back an overcharge within five years. Water follows local rules, and the five-year limit generally applies there too.

Do not wait. Claim any overcharge in writing, and challenge a back-billed amount in writing, as soon as you spot it.

Do you have to pay while you dispute?

Yes, keep paying what you do not dispute. A complaint does not stop a cut-off by itself.

• Electricity and gas: supply can be cut only after a written notice and the minimum notice period, and not on Fridays, weekends or holidays. Households covered by the bono social have extra protection.
• Water: it is treated as essential, and cuts need prior notice under regional rules. Ask your operator for the local procedure.
• Phone: the operator can suspend service for non-payment. A debt that is genuinely contested through an open complaint should not be put on a debt-default list.

The choice of how to pay is in the decision block below. Whatever you choose, keep proof of every payment and of your complaint.

If a cut-off notice arrives

Read the date. Send your complaint reference and proof of payment of the undisputed part to the provider straight away, and contact your consumer authority at once. Cut-off timing for electricity is covered on the page about unpaid bills and cut-offs.

Choosing between options

Should you pay the disputed amount while you challenge the bill?

• Pay the part you do not dispute: The error affects only some lines of the bill and you want to avoid a cut-off over the rest.

• Pay everything under protest and reclaim later: You cannot risk losing the supply and want to keep your right to get the overcharge back.

• Deposit the disputed amount (consignación): You want to show you are willing to pay while the amount is still contested.

Disputing a bill does not stop a cut-off by itself, so pay what is not in dispute and keep proof of your complaint. Electricity can be cut only after a written notice giving at least 30 days. If you are a vulnerable consumer, ask for the bono social status.

Timeline and deadlines

• Send a written complaint to the provider's customer service and ask for a reference number: as soon as you spot the error

• Wait for the provider's answer: one month for electricity, gas and telecoms

• Escalate to the regional consumer authority or the consumer arbitration board; for telecoms, to the telecoms user office: if there is no reply or an unsatisfactory one after one month

• Keep paying what is not disputed, since a complaint does not stop a cut-off; electricity can be cut only after a notice giving at least 30 days: while the complaint is open

• Claim back any overcharge or challenge a back-billed amount in writing: within five years for electricity and gas

Documents you need

• The disputed bill, plus your previous bills to compare consumption and prices.

• Bank statements showing the payments, to spot duplicate direct debits.

• Your supply contract, with its price and tariff conditions.

• A photo or note of your meter reading, and your consumption history from the distributor's portal or smart-meter data.

• An itemised invoice, which you can request from the provider.

• Proof of your complaint, such as the complaint reference number or the receipt from a registered letter or online form.

Checklist

• Compare the meter reading with the one on the bill, and check whether the bill is estimated.

• Check your consumption history in the distributor's portal or your smart-meter data.

• Check your contract for the tariff, contracted power (potencia) and price conditions, and compare with previous bills.

• Look through your bank statements for duplicate direct debits or charges for services you did not request.

• Ask the provider for an itemised invoice.

• Send a formal complaint (reclamación) to the provider's customer service by a channel that leaves proof, such as a registered letter or an online form with receipt.

• Claim any overcharge in writing within five years for electricity and gas.

Formal complaint letter (reclamación) to a utility or telecom provider

Send this letter to the provider's customer service department (servicio de atención al cliente). Fill in the blanks, keep the Spanish version as the one you send, and keep the English version for your own records.

How to send it so you have proof

• Best proof: a burofax with certified content and acknowledgement of receipt, sent from a Correos office. It proves the exact text and the date. It costs more than the other options, so it suits a large sum or a dispute that is likely to continue.
• Cheaper: the provider's online form or customer area, as long as it gives you a receipt or reference. Save a screenshot or PDF of the confirmation.
• Also fine: registered post with acknowledgement of receipt (carta certificada con acuse de recibo). It proves delivery but not what was inside, so keep a copy of the letter.
• Email: free and quick. Use it for a first contact, and keep the sent message and any reply.

Whichever route you use, ask for a complaint reference number and write down the date you sent the letter. Attach copies, never originals.

Letter in Spanish (send this one)

Asunto: Reclamación por factura incorrecta – contrato n.º [número de contrato]

[Ciudad], a [fecha]

A la atención del Servicio de Atención al Cliente de [nombre de la empresa]

Datos del reclamante:

• Nombre y apellidos: [su nombre completo]
• DNI/NIE: [su número]
• Dirección: [su dirección completa]
• Teléfono y correo electrónico: [sus datos de contacto]
• Titular del contrato (si es otra persona): [nombre y DNI/NIE]

Datos del contrato:

• Número de contrato o de cliente: [número]
• Código CUPS (solo luz y gas): [código CUPS]
• Dirección del suministro o servicio: [dirección]

Hechos

El [fecha] recibí la factura n.º [número de factura], de fecha [fecha], por importe de [importe] €. Esta factura es incorrecta porque [explique con claridad qué falla: lectura errónea, importe cobrado de más, servicio no contratado, cargo duplicado, etc.]. [Si ya reclamó antes: Ya me puse en contacto con ustedes el [fecha] por [teléfono/correo/formulario], con número de referencia [referencia], sin obtener solución.]

Solicitud

Por todo lo anterior, solicito que:

1. Revisen la factura indicada y la corrijan.
2. [Me devuelvan la cantidad de [importe] € cobrada indebidamente / anulen el cargo / cancelen el servicio no contratado.]
3. Suspendan cualquier corte o recargo mientras se resuelve esta reclamación.
4. Me respondan por escrito y me indiquen el número de referencia de esta reclamación.

Si no recibo respuesta en el plazo de un mes, acudiré a los organismos de consumo competentes.

Documentación adjunta

• Copia de la factura n.º [número]
• [Copia de lecturas, fotografías, contrato o reclamaciones anteriores]
• Copia de mi DNI/NIE

Atentamente,

[Firma] [Nombre y apellidos]

Letter in English (for your records)

Subject: Complaint about an incorrect bill – contract no. [contract number]

[City], [date]

For the attention of the Customer Service Department of [company name]

Claimant's details:

• Full name: [your full name]
• DNI/NIE: [your number]
• Address: [your full address]
• Phone and email: [your contact details]
• Contract holder (if someone else): [name and ID number]

Contract details:

• Contract or customer number: [number]
• CUPS supply code (electricity and gas only): [CUPS code]
• Address of the supply or service: [address]

Facts

On [date] I received invoice no. [invoice number], dated [date], for [amount] €. This invoice is wrong because [explain clearly what is wrong: incorrect reading, overcharge, service I did not order, duplicate charge, etc.]. [If you have already complained: I contacted you on [date] by [phone/email/form], reference number [reference], and the problem was not solved.]

Request

I therefore ask you to:

1. Review the invoice above and correct it.
2. [Refund the [amount] € charged in error / cancel the charge / cancel the service I did not order.]
3. Suspend any disconnection or surcharge while this complaint is being resolved.
4. Reply to me in writing and give me the reference number of this complaint.

If I do not receive a reply within one month, I will go to the competent consumer authorities.

Attached documents

• Copy of invoice no. [number]
• [Copies of meter readings, photos, contract or earlier complaints]
• Copy of my DNI/NIE

Sincerely,

[Signature] [Full name]

After you send it

Keep the burofax receipt, the online confirmation or the sent email together with a copy of the letter. If the provider rejects the complaint or stays silent after one month, you can take it to the consumer authority. For telecoms, that is the telecoms user service office (Oficina de Atención al Usuario de Telecomunicaciones). For electricity, gas and water, it is your regional consumer office or your town's consumer office (OMIC). The exact body depends on your region and the type of service, so ask your town hall's consumer office which one applies to you.

Frequently asked questions

How far back can a supplier correct a bill or must it refund an overcharge?

For electricity and gas, the limit for both back-billing and refund claims is five years. Water follows local rules, but the five-year limit generally applies there too. Put your claim in writing to the supplier first.

Will a disputed telecom bill put me on a debt list?

No, not if the debt is genuinely contested and you have an open complaint with the telecoms user office (Oficina de Atención al Usuario de Telecomunicaciones). Operators can still suspend your service for non-payment. Keep proof of your complaint.

What can I do if the provider ignores my complaint?

Take it to the regional consumer authority, or to the consumer arbitration board (Junta Arbitral de Consumo) if your provider has joined it. For telecoms, use the telecoms user office. Your town's consumer office (OMIC) or a court are further options.