Bulk SMS in Colombia: Law 2300, CRC, Sender ID and Consent
Bulk SMS Colombia guide (SMS masivo): Law 2300 sending hours, CRC excluded-numbers register, Law 1581 consent, Claro, Movistar, Tigo, Spanish accents.
By OmniChannels.ai Editorial Team · Reviewed by BroadNet Messaging Solutions Team
SMS & OTP
Short answer
To send bulk SMS in Colombia (SMS masivo), use a provider with routes to Claro, Movistar and Tigo, send advertising SMS only Monday to Friday 07:00 to 19:00 and Saturday 08:00 to 15:00, never on Sundays or public holidays (Law 2300 of 2023), and hold prior, informed authorisation under Law 1581 of 2012. Respect the CRC excluded-numbers register, include an opt-out, and expect accented Spanish to use Unicode at 70 characters.
On this page
- What rules apply to bulk SMS in Colombia?
- When can you send advertising SMS in Colombia?
- What are the opt-out and excluded-numbers duties?
- What does Law 1581 of 2012 require before you send?
- Which operators carry SMS in Colombia?
- Which sender type should you use: alphanumeric, long code or short code?
- How do Spanish accents affect SMS length?
- How should you separate OTP and promotional traffic?
- Where does WhatsApp fit next to SMS in Colombia?
- A worked example: an online store in Bogotá
- What are the common mistakes?
- How OmniChannels.ai helps
Key takeaways
- Law 2300 of 2023 applies the contact hours of its Article 3 to advertising SMS (Article 5, paragraph 3): Monday to Friday 07:00 to 19:00 and Saturday 08:00 to 15:00, with no contact on Sundays or public holidays. Our regulation data records the same window and treats transactional traffic as 24/7.
- Law 2300 requires senders to provide an agile, simple and efficient way to cancel at any time, and it ties into the CRC's Registro de Números Excluidos, the register of numbers that do not want advertising.
- Law 1581 of 2012 requires prior, informed authorisation of the data subject, obtained by any means that can be consulted later, unless an exception applies. Our regulation data calls for verifiable opt-in with retained records.
- Three networks appear in our coverage data, all with direct routes: Claro Colombia (732-101), Movistar Colombia (732-123) and Tigo Colombia (732-103). Sender formats are alphanumeric where supported, or numeric long codes and short codes.
- Spanish vowels with an accent (á, í, ó, ú) are outside the default GSM-7 alphabet, while é, ñ, ü and the inverted marks ¿ and ¡ are inside it, so accented copy is usually Unicode at 70 characters.
This guide is for retail, fintech, education and service teams that want to send business SMS to mobile numbers in Colombia: OTPs, delivery alerts, reminders and promotions. It explains the sending-hours rule in Law 2300 of 2023, how the CRC excluded-numbers register fits in, what Law 1581 of 2012 means for consent, and how Spanish accents change message length. It is a practical overview, not legal advice; confirm requirements with Colombian counsel and the operators before you launch.
What rules apply to bulk SMS in Colombia?
Four layers apply: Law 2300 of 2023 on advertising contact, Law 1581 of 2012 on personal data, the CRC's telecom regulation, and operator policy. Together they set hours, consent and opt-out duties.
| Layer | What it covers | Where to check |
|---|---|---|
| Law 2300 of 2023 | Hours and frequency for contact; advertising SMS; opt-out mechanism; excluded-numbers register | Función Pública |
| Law 1581 of 2012 | Personal data processing; prior, informed authorisation | Función Pública |
| CRC | Telecom regulator; runs the excluded-numbers register | crcom.gov.co |
| Claro, Movistar, Tigo | Sender types, routes, filtering | Your provider confirms at onboarding |
Our regulation data lists the CRC as the regulator and records the Law 2300 sending window. Always check the current text, because secondary summaries of these laws differ in detail.
When can you send advertising SMS in Colombia?
Advertising SMS may be sent only Monday to Friday between 07:00 and 19:00 and Saturday between 08:00 and 15:00, never on Sundays or public holidays. Article 3 of Law 2300 of 2023 sets these hours, and paragraph 3 of Article 5 applies them to advertising messages sent by SMS, messaging apps or web, email and commercial phone calls. Our regulation data records the same window and runs transactional traffic 24/7.
| Day | Advertising SMS allowed |
|---|---|
| Monday to Friday | 07:00 to 19:00 |
| Saturday | 08:00 to 15:00 |
| Sunday and public holidays | No |
Practical consequences:
- Schedule in Colombian time (UTC-5), not in your own time zone, and cut off sends so they cannot spill past 19:00.
- Do not queue promotions overnight and let them release the next morning in bulk without checking the calendar for public holidays.
- Keep OTPs and alerts separate. The hours rule concerns advertising; a login code or order status is a different kind of message, but anything with an offer inside becomes advertising.
The send time planner helps with scheduling, and SMS marketing rules by country compares hours across markets.
What are the opt-out and excluded-numbers duties?
You must give people an easy way to stop receiving messages, and you must respect the CRC register of excluded numbers. Law 2300 requires the sender to enable "a mechanism that is agile, simple and efficient" to cancel receipt of messages at any time. It also says consumers cannot be forced to accept commercial messages when they buy something or enter a store, other than messages strictly related to what they bought, and that when promotions are used to build databases the person must know and explicitly accept it.
The same law asks the government and the CRC to adapt the Registro de Números Excluidos so that it covers advertising by SMS, messaging apps, email and calls. Enrolled numbers should not receive advertising from you. Confirm the current technical process on the CRC site, because operators and the CRC specify how the register is applied.
Our regulation data lists a STOP keyword as honoured network-wide; add a clear Spanish instruction, test the keyword you choose, and apply every opt-out to all channels. Definitions: opt-out and DND registry.
What does Law 1581 of 2012 require before you send?
You need prior, informed authorisation from the person, obtained by any means that can be consulted later, unless a legal exception applies. Article 9 of Law 1581 sets that rule, and Article 10 lists the exceptions, such as data requested by a public authority or public-nature data; marketing to people who never agreed is not among the simple cases to rely on.
A safe routine follows:
- Capture authorisation with a record: the wording shown, date and time, channel and number.
- State the purpose clearly: say that you will send commercial messages by SMS, and who is sending.
- Keep proof you can retrieve later, as the law expects.
- Honour opt-outs at once and share the suppression list across channels.
- Do not buy lists. Purchased numbers have no authorisation trail.
Our regulation data calls for verifiable opt-in with consent records retained. Use the opt-in consent generator to draft wording, and read opt-in consent across channels for record keeping. Definition: opt-in.
Which operators carry SMS in Colombia?
Three mobile networks appear in our coverage data, each with a direct route.
| Operator | MCC-MNC |
|---|---|
| Claro Colombia | 732-101 |
| Movistar Colombia | 732-123 |
| Tigo Colombia | 732-103 |
Our regulation data names Claro and Movistar in its sender line and our coverage data adds Tigo, so confirm sender handling on all three. Read delivery reports per operator; our guide to improving SMS delivery rates shows how to diagnose a weak network.
Which sender type should you use: alphanumeric, long code or short code?
Our regulation data lists alphanumeric sender IDs where supported, numeric long codes and short codes for Colombia. Choose by what the message must do.
| Sender type | Best for | Watch out for |
|---|---|---|
| Alphanumeric (up to 11 characters) | One-way brand messages and alerts where supported | Not on every route; usually cannot receive replies |
| Numeric long code | Two-way conversations | Lower throughput; less branding |
| Short code | High-volume or keyword programmes | Longer set-up; code costs |
The operators set the requirements and our typical lead time is 5 to 10 business days; treat it as typical, not guaranteed. The sender ID checker and the Colombia sender ID page show the current position, and SMS sender ID types explained compares the formats. If you want us to prepare and file the registration with you, see registrations; approval decisions stay with the operators and regulators. Definitions: alphanumeric sender ID, long code and short code.
How do Spanish accents affect SMS length?
Plain Spanish fits the 160-character GSM 7-bit alphabet only if every character is in it. The alphabet includes é, ñ, ü, ¿ and ¡, but not á, í, ó or ú, so a single "código" or "sábado" turns the whole message into Unicode with 70 characters (67 per part). See GSM-7, Unicode SMS 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 (synthetic brand "Tienda Sol"):
| Message | Encoding | Characters | Parts |
|---|---|---|---|
Tienda Sol: tu codigo es 482913. No lo compartas con nadie. |
GSM-7 | 59 | 1 |
Tienda Sol: tu código es 482913. No lo compartas con nadie. |
Unicode (ó) | 59 | 1 |
Tienda Sol: tu pedido 1042 sale hoy y llega mañana antes de las 6 p. m. |
GSM-7 | 71 | 1 |
Tienda Sol: tu cita es mañana a las 10:00 en la sede Chapinero. |
GSM-7 | 63 | 1 |
Tienda Sol: tu cita es mañana a las 10:00 en la sede Bogotá. |
Unicode (á) | 60 | 1 |
Tienda Sol: 20% de descuento en zapatos hasta el sabado. Detalles: tiendasol.example/z Responde STOP para no recibir mas. |
GSM-7 | 121 | 1 |
Tienda Sol: 20% de descuento en zapatos hasta el sábado. Detalles: tiendasol.example/z Responde STOP para no recibir más. |
Unicode | 121 | 2 |
Rows 3 and 4 show that "mañana" costs nothing, because ñ is in the alphabet, while "Bogotá" does. Many brands drop accents in OTPs and alerts and keep correct spelling in campaigns where a second part is acceptable. Decide deliberately and check copy in the SMS character counter; see SMS character limits and Unicode.
How should you separate OTP and promotional traffic?
Keep OTPs, order alerts and service messages on a transactional sender and route, and promotions on their own. A promotion inside an OTP puts login codes at risk if the promotional route is filtered, and it can bring the message under the advertising hours rule.
| Traffic | Example | Practice |
|---|---|---|
| Transactional | OTP, payment confirmation, delivery alert | No promotion inside; own sender; any hour |
| Promotional | Sale, new product, loyalty offer | Authorised numbers only; opt-out; inside Law 2300 hours; check the excluded register |
| Mixed | "Tu pedido salió. Tienes 10% en la próxima" | Avoid; the offer makes it advertising |
For OTP design, read the OTP authentication messages guide and use the OTP message generator.
Where does WhatsApp fit next to SMS in Colombia?
Use SMS for reach, OTPs and fallback, and WhatsApp for richer conversations with customers who have opted in. WhatsApp supports media, buttons and replies; SMS reaches any handset without an app. Law 2300 also lists messaging apps among the channels covered by the advertising rules, so the hours and opt-out duties apply to WhatsApp marketing as well. See WhatsApp vs SMS vs RCS and channel fallback strategy.
A worked example: an online store in Bogotá
"Tienda Sol" (synthetic) sells shoes online and in six shops, and wants OTPs, delivery alerts and a Friday promotion.
- It registers a transactional and a promotional sender, and tests both on Claro, Movistar and Tigo.
- It asks for authorisation at checkout in a separate box, stating that it will send commercial SMS, and stores the wording, timestamp, channel and number.
- OTPs and alerts use short copy with no promotion; accents are kept only where the part count stays at one.
- The Friday offer is checked against its suppression list and the CRC register, scheduled to finish well before 19:00 Colombian time, and ends with a clear instruction to stop.
- A holiday calendar blocks promotions on public holidays and Sundays.
What are the common mistakes?
- Sending promotions outside the hours window, or letting a queue release on a Sunday or holiday.
- Ignoring the excluded-numbers register. Consent from a customer does not remove duties you cannot see from your own list.
- No retrievable proof of authorisation. The law expects consent that can be consulted later.
- One sender for everything. A filtered promotion can take OTPs down with it.
- Unplanned accents. One á turns a 160-character message into a 70-character one.
- Treating lead times as promises. Add buffer beyond 5 to 10 business days.
How OmniChannels.ai helps
OmniChannels.ai is powered by BroadNet, which has direct routes to Claro, Movistar and Tigo in our coverage data. We prepare and file sender registration with you, support Spanish content, scheduled sends and WhatsApp with SMS fallback, and give you per-operator delivery reports, with SMPP 3.4 for high volume. For indicative list prices, see the Colombia 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 legal in Colombia?
Yes. Businesses send OTPs, alerts and marketing SMS, provided they use a legitimate route, hold the data subject's authorisation, respect the permitted hours for advertising and honour opt-outs and the excluded-numbers register. The rules come from Law 2300 of 2023, Law 1581 of 2012, the CRC and the operators. Confirm details with Colombian counsel.
What hours can you send advertising SMS in Colombia?
Law 2300 of 2023 limits advertising SMS to Monday to Friday between 07:00 and 19:00 and Saturday between 08:00 and 15:00, with no contact on Sundays or public holidays. Schedule campaigns inside that window in Colombian time (UTC-5). Our regulation data treats transactional messages such as OTPs as running 24/7.
What is the Registro de Números Excluidos?
It is the register run by the CRC where people can enrol their numbers to avoid advertising messages. Law 2300 of 2023 extends it beyond SMS to messaging apps, email and calls. Check your lists against it, and confirm the current technical process on the CRC site, since operators may filter excluded numbers.
Do I need consent to send promotional SMS in Colombia?
Treat it as required. Law 1581 of 2012 requires prior, informed authorisation from the data subject, obtained in a way that can be consulted later, unless an exception applies. Our regulation data also calls for verifiable opt-in with retained records. Keep the wording, timestamp, channel and number for every opt-in.
Can I use a short code in Colombia?
Our regulation data lists short codes and numeric long codes as sender formats, alongside alphanumeric IDs where supported. Short codes suit high-volume or two-way programmes; alphanumeric IDs suit one-way brand messages. The operators set the requirements, and the typical lead time in our data is 5 to 10 business days, which is not a promise.
Why does my Spanish SMS split into two parts?
Letters such as á, í, ó and ú are not in the default GSM 7-bit alphabet, so one of them switches the whole message to Unicode, which holds 70 characters (67 per part). A promotion of 121 characters is one part without accents and two with them. Test the final copy in a character counter.
Sources
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