# Spain To send SMS and RCS to Spanish numbers with an alphanumeric sender, the alias must be registered with the CNMC. How the registration works, the two ways to do it, and the alias rules. **Language:** en **Audience:** platform **TLDR:** To send SMS to Spain with an alphanumeric sender, the alias must be registered with the CNMC (mandatory since 15 September 2026). You have two paths: let Instasent file it for you —and have your legal representative authorise it at sede.cnmc.gob.es— or register it yourself directly (faster). If you have no valid electronic certificate in Spain, an authorisation letter lets someone else act on your behalf. The alias is 3 to 11 characters, can't be generic, and a decision can take up to a month. **Translation key:** platform.channels.countries.spain **Search keywords:** spain, cnmc, alias registration, alias registry, sender registration, sender registration spain, alphanumeric sender, legal representative, legal profile, legal profiles, sede.cnmc.gob.es, authorise alias, authorize alias, alias authorisation, self-registration, register alias directly, authorization letter, authorisation letter, electronic certificate, digital certificate, cl@ve, filing, instasent files for you, proof of self-registration, file it myself, smishing, cnmc circular, required documents, what documents do I need **Related pages:** /platform/es/channels/countries/spain, /platform/en/channels/countries/spain/authorize, /platform/en/channels/countries/spain/self-register, /platform/en/channels/countries/spain/authorization-letters, /platform/en/channels/countries/spain/rejected, /platform/en/channels/sms/senders-registration, /platform/en/channels/rcs/senders-verification **Docs index (every page):** https://docs.instasent.com/llms.txt **This zone's index:** https://docs.instasent.com/platform/en/llms.txt **This page:** https://docs.instasent.com/platform/en/channels/countries/spain/ (HTML) · https://docs.instasent.com/platform/en/channels/countries/spain.md (Markdown) **Other language (es):** https://docs.instasent.com/platform/es/channels/countries/spain.md To send **SMS** to Spanish numbers with an alphanumeric sender, that sender must be registered with the **CNMC** (Comisión Nacional de los Mercados y la Competencia), in its Sender Alias Registry. Registration is equally **mandatory for RCS**, as an alias **independent** of the SMS one — registering one does not include the other. In Instasent, the CNMC process for RCS will switch on when the RCS channel launches — see [Does it apply to RCS too?](#does-it-apply-to-rcs-too). > **Warning**: **Registration is mandatory.** Since 15 September 2026, Spanish operators block > any **SMS** whose alphanumeric sender isn't registered (deadline set by Spain's > Orden TDF/558/2026). Register your senders before sending to Spain.{/* VERIFY: el panel interpola esta fecha en runtime desde regulation.enforcementDate; el backend cita hoy 2026-04-28 mientras que legal confirma el 15 de septiembre de 2026 — alinear el valor del panel con producto. */} ## How registration works Registration has two parts, and each one is done by a different person: the **alias details** are provided (the brand, the owner, the legal representative) and then the **legal representative authorises the alias** at the CNMC. The CNMC always notifies the legal representative, so their details have to be correct. ## How to register your alias: two paths You can register the alias in two ways, and both end with the legal representative authorising it at the CNMC's electronic office: - [Instasent files it for you](/platform/en/channels/countries/spain/authorize) - You provide the details in Instasent, Instasent files the alias in the CNMC Registry as the provider, and your legal representative only has to authorise it when they receive the CNMC's notification. - [You register it yourself](/platform/en/channels/countries/spain/self-register) - You submit the request yourself at the CNMC's electronic office. It's the fastest route: the decision usually comes through ahead of the bulk filing a provider does. > **Note**: No valid electronic certificate in Spain —for example, a foreign company— or > does your legal representative prefer to delegate? With an **authorisation > letter**, another person or entity that does hold a valid certificate acts on > their behalf. How it works and which template to use is in > [Registering the alias without an electronic certificate](/platform/en/channels/countries/spain/authorization-letters). ## What you provide The details aren't all asked at once, or in the same place: the legal profile holds **who you are**, and whatever the CNMC additionally requires is asked **when you file**. **On the legal profile** (**Settings → Organization → Legal Profiles**), creating one asks for two things: - **Brand details** — the alias and the brand it represents. - **Brand owner** — the company or person legally responsible for the alias. **What the regulator requires** comes later, in a second sheet called **Details for the regulator**, which appears inside the sender request once you pick a filing option: - **Legal representative** — the person who authorises the alias at the CNMC. The CNMC notifies this email, so it must be correct and reachable. - **Third parties** (optional) — intermediary agencies or related companies. - **The brand owner's registered address**, if you haven't set it yet. > **Note**: That second sheet **only appears if the profile is missing something** for the > option you chose. If it's already complete, you go straight through to the > request. And whatever you fill in there **is saved on the profile**, so it's > only needed once: the next sender you use with that profile won't ask again. You can also do it ahead of time, without waiting to request anything: open the profile under **Legal Profiles** and click **Add** (or **Edit**) on its regulator card. ## The Filing step in the sender request Spain adds one extra field to the country request you submit on the sender (the generic flow is in [SMS senders & registration](/platform/en/channels/sms/senders-registration)). When you request **Spain**, the form shows a **Filing** choice for the CNMC: - **I'll file it myself** — the **recommended** option, and the one selected by default. Pick it if you've already registered the alias with the CNMC yourself (see [Registering your alias directly](/platform/en/channels/countries/spain/self-register)), and supply the proof. - **Instasent files for you** — Instasent submits the alias to the CNMC registry on your behalf. Your legal representative still has to authorise it at the CNMC (see [Authorising the alias at the CNMC](/platform/en/channels/countries/spain/authorize)). The sender request also shows a card titled **Spain · CNMC** with the notice: **This country is regulated by CNMC, which will require every sender to be registered from 15 September 2026. After that, operators block messages from senders without a valid registration. Completing this step registers yours ahead of time.** ## How long it takes Plan for some lead time: once the alias is submitted to the CNMC, a decision can take **up to a month**. And if the CNMC doesn't respond within that window, the request is treated as denied (negative administrative silence) and has to be filed again from scratch. So request your sender with time to spare, and double-check that your legal representative's details are correct before submitting, to avoid losing that month. Registering yourself directly is usually quicker than waiting for the bulk filing a provider does, so if you're in a hurry, consider [self-registration](/platform/en/channels/countries/spain/self-register). If the CNMC rejects the registration, the rejection reason tells you what to do: sometimes filing again is enough, sometimes you need a different alias — see [Alias rejected by the CNMC](/platform/en/channels/countries/spain/rejected). ## Alias rules | | | | --------------- | ---------------------------------------------------------------------------------------------------------------------------------- | | **Length** | 3 to 11 characters | | **Allowed** | letters a–z and A–Z, digits 0–9, and `@ & - _ . +` | | **Not allowed** | numbers only, accented characters (á, é, í…), the symbols `! ? # % * € ( ) [ ]`, and generic names ("Banco", "Mensaje", "Urgente") | The alias must be genuinely and legitimately tied to your brand. The CNMC may reject one that is generic or that could cause confusion, fraud or impersonation. > **Note**: A rejected registration comes back with the reason. Fix the alias or the details > and resubmit. For the general sender flow and its states, see > [SMS senders & registration](/platform/en/channels/sms/senders-registration). ## Does it apply to RCS too? Yes. Registration with the CNMC is **also mandatory for RCS**, and it's a registration **independent** of the SMS one: the SMS alias and the RCS alias are registered separately, and **registering one does not include the other**. The CNMC portal already covers it — the [direct self-registration](/platform/en/channels/countries/spain/self-register) lets you choose the message type (SMS/MMS or RCS). **In Instasent, the CNMC process for RCS will switch on when the RCS channel launches** (with the new version of the App): the channel will carry the compliance that corresponds to it, and the RCS agent will go through the CNMC just like an SMS sender. Until then, an RCS agent in Spain doesn't go through the CNMC — it's cleared once the operators approve it. With RCS, the agent also has to be **approved by the operators**, and you need an **enabled provider** for RCS in Spain. You configure the RCS agent in [RCS senders & verification](/platform/en/channels/rcs/senders-verification). ## Regulation Alias registration comes from Spain's messaging regulation, designed to curb fraud (smishing) and impersonation: - **Orden TDF/558/2026** — sets the obligation and the date (15 September 2026). - **CNMC Circular 1/2026** — regulates the registry and the alias format (what can be registered, non-generic names). - **CNMC Circular 2/2026** — amends the previous one to allow acting through an **authorised representative** by means of an authorisation letter. - **CNMC electronic office** — [Sender Alias Registry management](https://sede.cnmc.gob.es/tramites/telecomunicaciones/gestion-del-registro-de-alias) and the official registration guide. --- This is one page of the Instasent documentation. For the complete machine-readable index of every guide and API reference, fetch https://docs.instasent.com/llms.txt — start there for full context.