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Bulk SMS in Switzerland: UWG Opt-in, Sender ID and FADP

Bulk SMS Switzerland guide: BAKOM, the UWG opt-in rule for mass advertising, revised FADP, Swisscom, Sunrise and Salt routes, and multilingual SMS.

Updated 9 min read

By OmniChannels.ai Editorial Team · Reviewed by BroadNet Messaging Solutions Team

SMS & OTP

Short answer

To send bulk SMS in Switzerland, use a provider with routes to Swisscom, Sunrise and Salt, and send advertising only to people who explicitly consented, because Swiss unfair competition law (UWG Art. 3 para. 1 lit. o) allows automated mass advertising by SMS only on an opt-in basis. Name the sender, offer a free and easy opt-out, and write German, French or Italian in GSM-7 to stay at 160 characters.

On this page
  1. What rules apply to bulk SMS in Switzerland?
  2. What does the UWG say about SMS advertising?
  3. What does the revised FADP add?
  4. How do sender IDs work in Switzerland?
  5. Which operators carry SMS in Switzerland?
  6. How should you separate OTP and promotional traffic?
  7. How do German, French and Italian affect SMS length?
  8. When should you send?
  9. A worked example: a Zurich optician chain
  10. What is a launch checklist for bulk SMS in this market?
  11. What are the common mistakes?
  12. How OmniChannels.ai helps

Key takeaways

  • BAKOM (the Federal Office of Communications) states that since 1 April 2007 automated mass advertising by e-mail, SMS, fax or telephone is allowed only if recipients have explicitly consented (UWG Art. 3 lit. o), with an exception for sellers advertising similar products to their own customers.
  • BAKOM also says the sender must be identifiable, it is forbidden to conceal the sender, and each message must give an easy, free way to refuse future messages.
  • The revised Federal Act on Data Protection (FADP) came into force on 1 September 2023 and applies to how you collect and store the numbers and consent records.
  • Our data lists Swisscom (228-01), Sunrise (228-02) and Salt (228-03), all with direct routes; sender IDs are set by the operators and alphanumeric IDs are up to 11 characters.
  • German, French and Italian text mostly fits GSM-7 (160 characters, 153 per part), but guillemets, curly quotes, emoji and letters such as ê, â, ô, û and a lowercase ç switch a message to Unicode at 70 (67).

This guide is for retailers, banks, insurers, healthcare providers and operations teams that want to send business SMS to mobile numbers in Switzerland: OTPs, appointment reminders, delivery alerts and promotions. It explains the Swiss opt-in rule, how the revised data protection act fits in, which operators carry traffic and how three national languages affect message length. It is a practical overview, not legal advice; confirm requirements with Swiss counsel before launch.

What rules apply to bulk SMS in Switzerland?

Three layers apply: the Federal Act against Unfair Competition (UWG) for advertising, the revised Federal Act on Data Protection (FADP) for personal data, and telecom rules and operator policy. Our regulation data lists the Federal Office of Communications (OFCOM, in German BAKOM) as the telecom regulator.

Layer What it covers Where to check
UWG Art. 3 para. 1 lit. o Opt-in for automated mass advertising by SMS, sender identification, easy refusal BAKOM
Revised FADP (in force 1 September 2023) Handling of phone numbers and consent records Federal Office of Justice
Operators (Swisscom, Sunrise, Salt) Sender ID set-up, routes, filtering Confirmed at onboarding

Our regulation data also asks for GDPR-style opt-in, with double opt-in as the operator-preferred standard for marketing.

What does the UWG say about SMS advertising?

It allows automated mass advertising by SMS only if recipients have explicitly consented. BAKOM describes the rule this way: since 1 April 2007, Art. 3 lit. o UWG has allowed automatic mass transmission of advertising by e-mail, SMS, fax or telephone only if recipients have explicitly given their consent, the opt-in system. BAKOM adds three points:

  • Existing customers. A seller who received a person's address through a purchase may send advertising for products of the same type.
  • Sender identification. The sender, or the party it acts for, must be clearly identifiable, and concealing the sender is forbidden.
  • Easy refusal. Every message must offer an easy, free way to refuse further messages, and the sender must tell the recipient about it.

A service message such as an OTP or a delivery alert is not advertising, but a promotion tucked inside one is. The page does not set deadlines for processing a refusal, so honour opt-outs immediately.

What does the revised FADP add?

It governs the personal data behind your campaign, and it came into force on 1 September 2023, replacing the 1992 Act. A phone number linked to a person is personal data, so how you collect, store, share and delete numbers and consent records falls under it. The UWG opt-in rule and the FADP both apply; satisfying one does not satisfy the other.

A safe routine:

  1. Capture consent with a record: wording shown, date, time, channel and number.
  2. Use double opt-in where possible, as our regulation data describes operators preferring.
  3. State who is sending and what they will send, in the customer's language.
  4. Honour opt-outs immediately and keep one suppression list across channels.
  5. Do not buy lists. Purchased numbers have no consent trail.

Our opt-in consent generator drafts consent wording, and the guide to opt-in consent across channels shows how to record it.

How do sender IDs work in Switzerland?

Business SMS to Switzerland can use an alphanumeric sender ID of up to 11 characters, and numeric long codes are also supported. Our regulation data says requirements are set by the operators and confirmed at onboarding, and it records no fixed lead time, so ask for a timeline during onboarding rather than assuming one.

Step What to do
1. Classify Separate transactional (OTP, reminders) from promotional traffic
2. Choose names Use your brand name; avoid names that imitate banks, posts or authorities
3. Prepare documents Company details and an authorisation letter naming the sender IDs and your provider
4. Submit Your provider files with the operators where required
5. Test Send an OTP and a promotion to Swisscom, Sunrise and Salt handsets

The sender ID letter generator drafts the letter, and the Switzerland sender ID page shows the current position. If you want us to prepare and file the registration, see registrations; approval decisions stay with the operators. Formats are explained in sender ID types.

Which operators carry SMS in Switzerland?

Three mobile networks appear in our coverage data, each with a direct route.

Operator MCC-MNC
Swisscom 228-01
Sunrise 228-02
Salt 228-03

Our regulation data names Swisscom and Sunrise in its sender ID entry, while our coverage data also lists Salt; confirm which networks your sender ID covers at onboarding. Read delivery reports per operator; see improving SMS delivery rates.

How should you separate OTP and promotional traffic?

Keep OTPs, appointment reminders and other service messages on a transactional sender ID and route, and promotions on their own. A promotion inside an OTP puts login codes at risk if the route is filtered and can turn the message into advertising.

Traffic Example Practice
Transactional OTP, parcel notice, appointment reminder No promotion inside; own sender ID; any hour
Promotional Sale, new collection, loyalty offer Opt-in only; sender named; free opt-out; daytime schedule
Mixed "Ihr Paket ist unterwegs. 10 % Rabatt auf Ihre nächste Bestellung" Avoid; the offer makes it advertising

For OTP content and security, read the OTP authentication messages guide.

How do German, French and Italian affect SMS length?

Most plain German, French and Italian text fits the default GSM 7-bit alphabet, so one message holds 160 characters (153 per part). The alphabet includes ä, ö, ü, ß, é, è, à, ù, ì, ò and an uppercase Ç. It does not include ê, â, î, ô, û, a lowercase ç, Swiss guillemets or curly quotes, and any of them switches the message to Unicode at 70 (67 per part). See GSM-7 and concatenated SMS.

Encoding Single message Per part when concatenated
GSM 7-bit 160 characters 153
Unicode (UCS-2) 70 characters 67

These examples were counted against the limits (Alpina Optik is a synthetic brand):

Message Encoding Characters Parts
Alpina Optik: Ihr Code lautet 482913. Bitte geben Sie ihn niemandem weiter. GSM-7 75 1
Alpina Optik: Rappel de rendez-vous demain à 14 h à Genève. Pour annuler: alpina.example/rdv GSM-7 92 1
Alpina Optik: Sonnenbrillen -20 % bis Sonntag. Info: alpina.example/s. Abmelden: alpina.example/stop GSM-7 100 1
Alpina Optik: Sonnenbrillen -20 % bis Sonntag. Info: alpina.example/s. Abmelden: alpina.example/stop (Aktion «Sonne») Unicode 117 2

The last row shows the cost of one pair of guillemets: the same message jumps from one part to two. Check final copy in the SMS character counter; see also SMS character limits and Unicode.

When should you send?

We have not found a regulator-published time-of-day window for promotional SMS in Switzerland, and our regulation data records none. Agree sending hours with the operators, send promotions in local daytime (Central European Time, with daylight saving) and avoid late evenings and Sundays. OTPs and reminders can go at any hour. The send time planner helps schedule, and SMS marketing rules by country compares markets.

A worked example: a Zurich optician chain

"Alpina Optik" (synthetic) has 20 shops in German-, French- and Italian-speaking regions, and wants appointment reminders, OTPs for its app and a seasonal offer.

  • It registers separate transactional and promotional sender IDs and tests both on Swisscom, Sunrise and Salt.
  • It collects explicit consent in the app and in-store, with double opt-in, the sender named and the customer's language saved.
  • Reminders are sent in the customer's language and kept to plain GSM-7 at one part.
  • The offer goes only to opted-in numbers, with a free opt-out and no curly quotes or emoji.
  • Opt-outs feed one suppression list that also covers WhatsApp and email.

What is a launch checklist for bulk SMS in this market?

Work through these steps in order before your first campaign; each one removes a common cause of blocked or undelivered messages.

  1. Confirm your use cases and split them into transactional and promotional traffic.
  2. Start sender ID work early, allowing for the timeline the operators confirm at onboarding, and name the IDs after your registered brand.
  3. Agree the consent source for every list, and store wording, timestamp, channel and number.
  4. Prepare opt-out handling: a named sender, a free opt-out and the customer's language, with one suppression list.
  5. Finish the templates in the right language and check each one in the character counter.
  6. Test on Swisscom, Sunrise and Salt handsets, including a delayed or failed delivery report.
  7. Set sending hours with the operators and schedule promotions for local daytime.
  8. Review delivery reports per operator after the first small send, then scale up.

Do not skip step 8: a small pilot to a consented group exposes filtering and formatting problems before they affect a full audience.

What are the common mistakes?

  • Assuming implied consent. The UWG rule is explicit opt-in, with a narrow existing-customer exception.
  • Hiding the sender. Concealing the sender is forbidden.
  • No simple refusal path in each promotion.
  • Typographic quotes and guillemets that double the part count.
  • Mixing OTP and promotion on one route.
  • Assuming a lead time that the operators have not confirmed.

How OmniChannels.ai helps

OmniChannels.ai is powered by BroadNet, which has direct routes to Swisscom, Sunrise and Salt in our coverage data. We prepare and file sender ID registration with you, support German, French and Italian content, and give you per-operator delivery reports, with SMPP 3.4 for high volume. For indicative list prices, see the Switzerland SMS pricing page, then book a demo. Small team? Our SMS marketing guide for small businesses covers the basics.

Frequently asked questions

Is bulk SMS marketing legal in Switzerland?

Yes, with prior explicit consent. BAKOM says that since 1 April 2007 automated mass advertising by SMS is allowed only if recipients have explicitly consented, an opt-in system under UWG Art. 3 lit. o. There is an exception for a seller advertising similar products to its own customers. Service messages such as OTPs are not advertising.

Do I need consent to send promotional SMS in Switzerland?

Treat explicit opt-in as required. Per BAKOM, the exception is narrow: a seller may advertise similar products to people who gave their address when buying. Even then the sender must be identifiable and every message must offer an easy, free way to refuse future ones. Keep a record of when and how each number agreed.

Does the revised FADP apply to SMS marketing?

It applies to the personal data involved, including phone numbers and consent records. The revised FADP came into force on 1 September 2023. It does not replace the UWG opt-in rule for advertising; you must satisfy both. Ask Swiss counsel about transparency duties and data subject rights for your set-up.

Do I need to register a sender ID in Switzerland?

Our regulation data says sender ID requirements are set by the operators and confirmed by BroadNet at onboarding, and records no fixed lead time. Alphanumeric IDs of up to 11 characters are supported, as are numeric long codes. Test delivery on Swisscom, Sunrise and Salt before a launch.

What languages should SMS use in Switzerland?

Switzerland has German, French and Italian speaking regions, plus Romansh. Choose the language per customer from sign-up or account data rather than sending several languages in one message, which multiplies the length. Most plain German, French and Italian text fits GSM-7, but some accented letters trigger Unicode.

Is there a time-of-day rule for SMS in Switzerland?

We have not found a regulator-published time-of-day window for promotional SMS in Switzerland, and our regulation data records none. Agree sending hours with the operators, send promotions in local daytime (Central European Time) and avoid late evenings and Sundays. OTPs and alerts can go at any hour.

Sources

  1. When is mass sending allowed? BAKOM, Federal Office of Communications
  2. Federal Office of Justice: Data protection legal bases (revised FADP)
  3. 3GPP TS 23.038: Alphabets and language-specific information

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