Spain’s new 400 prefix for commercial calls is due to be fully operational on 17 October 2026. It will help you recognise sales calls, but it will not make unwanted calls disappear. If you live in Spain and use a Spanish mobile number, this is a change you may notice on your phone rather than something you need to configure yourself.
This guide is written for English-speaking residents of Spain. It explains what a 400 call means, whether you can call back, who must use the new numbers, how to ask your Spanish operator about blocking them, and which authorities handle complaints. The information was checked on 5 October 2026, before the full implementation deadline.
What changes in Spain on 17 October 2026?
The resolution dated 14 April 2026 was published in Spain’s official gazette, the BOE, on 16 April and took effect the following day. It allowed six months for allocation, network preparation and changes to business calling systems. Spain’s telecom regulator, the CNMC, identifies 17 October 2026 as the deadline for the range to be fully operational.
This is not the day Spain first restricts unsolicited marketing. Consent and legitimate-interest safeguards have applied since 2023. Since June 2025, Spanish mobile numbering has also been prohibited for customer-service calls and unsolicited commercial calls. The new development is a visible number range separating sales calls from customer support.
Sources: the final 400 resolution in the BOE and the CNMC allocation decision.
What does a Spanish 400 number look like?
These are nine-digit Spanish numbers beginning with 400, for example 400 XXX XXX. They are not a new provincial area code or a short customer-support number. The range runs from 400 000 000 to 400 999 999, with numbers allocated to operators in blocks of 1,000 and subsequently supplied to companies.
The range is reserved for outbound commercial calls. A properly separated support call about an outage, complaint or existing contract should not use it. Do not confuse the domestic beginning 400 with an international country code: this article concerns Spanish telephone numbering and Spain’s regulations.
Do all companies in Spain have to use 400?
The scope is more nuanced than some headlines suggest. The first section of the final resolution expressly links the obligation to companies covered by Spain’s Customer Service Act, Ley 10/2025, including its transitional exceptions.
Who must use 400: a quick guide. This table summarises the scope explained below. It does not determine an individual business’s obligation on its own; its activity, size and applicable exceptions must be checked.
| Type of business | Must it use 400 for commercial calls? |
|---|---|
| Business in another sector meeting any of the Article 2.2 thresholds | In principle, yes, within the Act’s scope. |
| Provider of essential services covered by the Act | Yes, subject to the stated exceptions and sector-specific qualifications. |
| Small local business outside those sectors and below the thresholds | Not automatically included. |
| Self-employed business | Depends on the activity and applicable thresholds. |
| Electricity, gas or telephone-service supplier below 5% market share and outside the large-business thresholds | May qualify for the stated exception. Both conditions must be met. |
Essential services and large businesses
The Act includes providers of water, gas, electricity, passenger transport, postal services, electronic communications and financial services. Outside these sectors it applies to companies or groups which, in the previous financial year, employed at least 250 people, exceeded €50 million in annual turnover, or exceeded €43 million in annual balance-sheet total. Reaching one threshold is enough; membership of a group also matters.
A small local shop, hairdresser or installer outside the covered sectors is not automatically included simply because it makes a sales call. Being self-employed is not, on its own, a blanket exemption either: the activity and the applicable business thresholds determine the position.
The 5% exception
A transitional exception affects certain obligations of electricity, gas and telephone-service suppliers, including the numbering separation requirement. It applies while the company or its group remains below 5% of the national market and is also outside the large-business category in Article 2.2. A market share below 5% is not enough by itself.
Financial services also have sector-specific rules which take precedence where applicable. Identifying a particular business as exempt requires checking its circumstances, not guessing from the trading name on a caller’s script.
Why you may read that “all commercial calls” must use 400
There is a wording issue worth explaining. The first section defines the obligation by reference to the Act, while the second paragraph of the sixth section states exclusivity more generally after the six-month period. The CNMC’s public explanation says the business must be subject to the obligation and reminds readers that exceptions exist.
Our cautious interpretation is to read the deadline provision together with the express scope and exceptions. A sales call from an ordinary local business should not automatically be declared unlawful solely because it uses another range. A specific disputed case may require clarification from the authority. See the CNMC explanation.
Sales call or customer service? Everyday examples in Spain
The purpose of the conversation matters. Persuading you to buy differs from maintaining a contract or resolving a problem. The following examples are guidance rather than a classification ruling; the company’s legal scope still determines whether the 400 obligation applies.
| Reason for the call | Likely category |
|---|---|
| Offering a cheaper fibre package | Commercial |
| Confirming the installer’s appointment | Performance of an existing contract |
| Explaining an electricity bill or fixing an outage | Customer service |
| Trying to win back a former customer | Commercial |
| Offering a higher plan or new promotion | Commercial |
| Calling with a quotation you requested | Normally commercial, even though requested |
| Administrative reminder of an agreed renewal | May be contract management |
| Persuading you to renew or upgrade | Commercial |
| A satisfaction survey without a sales offer | Needs assessment of the actual call |
The Act also restricts exploiting certain essential-service complaints or interruptions to sell products. Exceptions include a request from the customer or a proposal linked to resolving the issue which improves the service conditions or price. That is not general permission to turn every support conversation into a sales pitch.
Does a call centre abroad escape the Spanish rules?
No general exemption follows from the agent being abroad. The Act addresses covered businesses established in Spain or another country that provide relevant services in Spanish territory. Outsourcing and the location of the communication point do not automatically remove the business’s obligations.
There is a separate technical question. The CNMC says operators must block 400 calls received from abroad, unallocated numbering, and their own numbers not assigned to a customer. Where an agent sits is different from how the call enters the network. A legitimate overseas centre may use a properly provisioned operator service, but an international incoming call displaying a Spanish 400 identifier is not automatically permitted. The exact routing arrangements depend on the providers.
Can you call a 400 number back?
No. The final rules allow outbound calls only and prohibit calls with a 400 number as the destination. If you miss a call and want to discuss the offer, find the company’s customer-contact number independently through its official website, app or your contract.
This is especially useful for residents reading older English-language coverage. The February proposal described two-way numbering; the final April resolution changed the design. Information saying you can return the call may be describing the proposal rather than the adopted rules. There is no universal recorded message specified for unsuccessful callback attempts.
How to ask your Spanish operator to block 400 calls
The final resolution permits operators to offer disconnection from commercial calls using this range at a customer’s request. That wording enables an option; it does not establish the same mandatory blocking button at every operator. Check availability for your particular line, how to activate it and how to undo it.
You can ask in Spanish:
«¿Ofrecen el bloqueo de todas las llamadas comerciales del rango 400 en mi línea? ¿Cómo se activa y se desactiva?»
This means: “Do you offer blocking of all commercial calls from the 400 range on my line? How do I turn it on and off?” Ask for written confirmation through your account or the operator’s official support channel.
Blocking the whole range may also prevent a requested quotation or offer reaching you. Customer support should be separate, but that does not make a blanket filter suitable for every situation.
Phone blocking is a different feature
Blocking one number is not the same as blocking an entire prefix. Phone settings vary by operating system, manufacturer, app and version. Check the Phone app’s spam identification and filtering settings; do not assume typing 400* works on every Android phone or iPhone. Silencing unknown callers can also hide useful calls from tradespeople or services you have not saved.
Does a 400 number mean the caller is safe?
The number indicates the declared commercial purpose within a regulated range. Network checks can make basic spoofing harder, but they do not certify a caller’s honesty, the quality of the offer or your consent. A properly supplied number could still be abused, and social engineering remains possible.
If a caller demands banking passwords, verification codes or an urgent payment, end the call and verify the request using a contact route you obtained independently. This applies even when the caller speaks fluent English and appears to know details about your home or contract.
Your marketing rights in Spain still apply
Human marketing calls need consent or another valid basis, such as legitimate interest subject to the applicable safeguards. A previous customer relationship can support offers of the company’s own similar products or services. It is not unlimited permission to promote unrelated services or share your details with another group company without the specific consent required.
Lista Robinson, Spain’s advertising exclusion service, remains relevant, as do withdrawing consent and objecting to further marketing. Automated calls without human intervention need prior consent. These are Spanish and EU protections: being an English-speaking resident does not turn the issue into a US telemarketing complaint.
At the beginning of the call, the caller should identify the business, any company on whose behalf it acts, its commercial purpose and your right to withdraw consent or object. See the AEPD explanation of lawful human marketing calls.
A useful sentence is: «Me opongo a recibir más llamadas comerciales. Registren mi oposición». It means: “I object to receiving further marketing calls. Please record my objection.” When possible, repeat the request in writing through an official channel and keep a copy.
How to report unwanted calls in Spain
Keep a screenshot of the call log, the number, date and time, the business name and the company represented, the purpose of the call and previous opt-out evidence. A recording or other evidence that identifies the caller helps. Your line contract or bill can establish that you are the subscriber or an authorised user.
The AEPD is Spain’s data protection authority and handles personal-data, consent and objection issues. For misuse of telephone numbering, the Ministry points to the Oficina de Atención al Usuario de Telecomunicaciones (OAUT) and/or the CNMC. Consumer authorities or sector regulators may be relevant depending on the breach. A number alone is not always enough to identify the responsible business.
Use the AEPD’s official complaint evidence checklist for current requirements and procedural timing. To explore advertising exclusion, visit Lista Robinson. These are the relevant Spanish routes for this guide.
What if you sign up during an unlawful sales call?
Ley 10/2025 changes Article 62 of Spain’s consumer legislation. For telephone contracts made in breach of unsolicited-calling rules, it introduces a presumption that the consumer did not intend to contract and nullity of the contract. Within that context, it also addresses consent expressly obtained or renewed during the two years before the call leading to the contract.
Do not simplify this into a universal expiry date for all marketing consent. The provision concerns telephone contracting and contains special treatment for certain loans or credit after funds have been delivered. Keep the paperwork and seek assessment through the appropriate complaint channel rather than deciding a particular agreement’s status from a general explainer. See the consumer-law amendment.
Is there a fixed fine for calling without 400?
The 400 resolution does not provide a single fixed fine per call. Numbering, consumer protection and data protection have different enforcement regimes. The relevant authority must assess the facts, the rule breached and the circumstances. Maximum penalties from another regime should not be presented as “the fine for a spam call”.
Does answering a 400 call cost money?
The 400 range is not a premium-rate callback service such as 803, 806 or 807, nor a conventional 901/902 return number. There is no special surcharge for answering simply because it begins with 400. If you live in Spain with a foreign SIM or receive calls while roaming outside your usual tariff area, check your own provider’s roaming terms: any charge comes from that arrangement, not from 400 being premium.
Which 400 numbers have already been assigned?
The CNMC’s July initial allocation comprises 98 blocks of 1,000 numbers. Examples in the annex include 400120xxx for Digi Spain Telecom, 400171xxx for Euskaltel and 400250xxx for Orange Business Spain.
An operator’s allocation is not a trusted list of brand sales numbers. Operators supply numbers to business customers. Do not infer that a call using one of these blocks is definitely from that operator’s consumer brand. The CNMC annex identifies allocations, not the credibility of an offer.
What remains to be clarified in practice?
Watch for operator-specific blocking availability, treatment of mixed-purpose calls, brands publishing their own contact numbers, and any further clarification of the general wording in section six. The 17 October numbering deadline also differs from the Act’s general twelve-month customer-service adaptation period, which leads to December 2026.
Spain 400 prefix: frequently asked questions for residents
Will spam calls end on 17 October?
No. The 400 range helps identify sales calls and apply controls; it cannot guarantee an end to unwanted calls or scams.
Can I return a missed 400 call?
No. The final range is outbound only. Contact the business through an independently verified channel.
Do I have to change my phone number?
No change to your own number is required merely to receive these calls. The new range concerns businesses’ outbound commercial numbering.
Can I block the entire prefix?
Ask your Spanish operator whether it offers the service. Handset prefix filtering is not universal.
Is every non-400 sales call automatically illegal?
Do not decide from the number alone. The business’s scope, exceptions and calling safeguards matter.
For daily life in Spain, the benefit is a recognisable signal before answering. Learn what it indicates, ask about filtering if useful and keep your marketing rights in mind. Verify sensitive requests independently regardless of the number on the screen.
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