Bulk SMS in the DRC: the complete guide for businesses (2026)

Bulk SMS in the DRC lets you reach customers, students or members on any mobile phone in the Democratic Republic of the Congo, whether or not it is connected to the internet. Bulk SMS means sending the same message, or a personalised one, to a list of numbers from a web platform or an API. This guide covers what a business needs to know, from Kinshasa to Lubumbashi: numbers, Sender ID, pricing, campaigns, API and the rules to follow, with figures from ARPTC, the DRC’s telecoms regulator.

Why is SMS still essential in the DRC?

SMS works on every mobile phone, from the most basic handset to a smartphone, with no data plan and no app. In the DRC, where most people do not use the internet, it is the written channel that reaches the most people.

According to ARPTC’s report on the first quarter of 2026, published in June 2026, the DRC had 74,969,343 active mobile subscriptions at the end of March, a penetration rate of 66.8%, but only 38.2 million mobile internet subscriptions. DataReportal reaches the same conclusion: at the end of 2025, 69.5% of the population, or 79 million people, did not use the internet.

SMS is losing ground as a way for people to chat, though: according to ARPTC, total SMS traffic fell 15.84% in one quarter as people moved to messaging apps, and SMS is refocusing on business uses (OTP codes, transaction confirmations, alerts). Almost 12 billion SMS still went through the networks in the first quarter of 2026.

SMS or WhatsApp: which should you use?

The two complement each other: SMS works on every mobile phone without an internet connection, while WhatsApp supports conversations with customers who have the app and a connection.

Many businesses use both. Our WhatsApp Business API guide covers the second channel.

Phone numbers and mobile operators in the DRC

A Congolese mobile number is written +243 followed by 9 digits; in national format, you dial 0 followed by those 9 digits. Four operators share the market: Vodacom, Airtel, Orange and Africell.

Which number format should you use for bulk SMS?

After the country code, mobile numbers start with 8 or 9 (08 or 09 in national format). For bulk SMS, drop the leading 0 and add the 243 country code: 0812345678 becomes +243812345678. On Coussema, a valid number has 12 digits and starts with 243 or +243, with no 0 right after it.

Who are the mobile operators in the DRC?

Subscriptions and market shares: ARPTC, first quarter of 2026. Prefixes: an indicative list of the main ranges, from the e164.com numbering database (October 2026).

No need to sort contacts by operator: a multi-operator platform such as Coussema routes each number to the right network.

Marketing SMS vs transactional SMS: what is the difference?

A marketing SMS promotes an offer to a list of contacts. A transactional SMS delivers information that one person expects after an action: an OTP code, a payment confirmation, an appointment reminder.

An OTP (one-time password) is a single-use code that confirms a login or a transaction. The difference matters legally too: the DRC’s Digital Code defines direct marketing (“prospection directe”) as any message meant to promote goods, services or the image of the person selling them. A marketing SMS falls under it; an OTP code does not.

SMS examples by sector in the DRC

Each example fits in one SMS. Many messages in the DRC are written in French, the official language: watch the accents covered below.

Sender ID in the DRC: sending under your business name

A Sender ID is the name displayed as the sender of an SMS instead of a phone number: “MyBank” rather than “+243 81…”. Recipients recognise the business as soon as the notification appears.

How many characters can a Sender ID have?

Eleven at most. In the GSM standard, the sender address field is limited to 12 bytes, header included (3GPP TS 23.040), which leaves room for 11 alphanumeric characters.

On Coussema, a Sender ID has 3 to 11 characters: unaccented letters, digits, spaces, hyphens and underscores, starting with a letter or a digit. “MonEcole” is accepted, but “MonÉcole”, with an accent, is not.

Why does a Sender ID build trust?

An SMS signed with your brand name is recognised at a glance, while an unknown number can look like fraud. Note that nobody can reply to a Sender ID: if you want answers, include a number in the message.

How do you get a Sender ID with Coussema?

The Sender ID is free. You request it in the dashboard by describing your business, your messages and where your contacts come from, with a sample SMS. Once approved, it works in your campaigns and in the API. It is part of the Growth plan, not the free Starter plan.

How much does an SMS cost in the DRC?

With Coussema, an SMS to the DRC costs $0.03 on the Growth plan, with no subscription. The Starter plan is free, with 10 free SMS when you sign up, and high-volume senders can request a custom quote for the Enterprise plan. Purchased SMS never expire and are paid by Mobile Money (details on the pricing page).

What is an SMS segment?

A segment is the basic unit of an SMS: up to 160 characters in standard encoding. A longer message travels as several segments that the phone puts back together, each billed as one SMS. Each segment then holds only 153 characters, because it carries a small header used to reassemble the parts in order (3GPP TS 23.038 and TS 23.040).

In Unicode, most emojis count as two characters.

A few symbols stay in GSM-7 but count as two characters: € [ ] { } \ ^ ~ |.

Which characters switch an SMS to Unicode?

A single character missing from the GSM alphabet switches the whole message to Unicode:

• Accepted in GSM-7: é, è, à, ù, ì, ò, É and capital Ç.
• Switch to Unicode: ê, â, î, ô, û, ë, ï, lowercase ç, œ, À, È, Ê, curly apostrophes and quotes (’ “ ”), French « » quotes, the ° sign in “n°”, and emojis.

Coussema’s editor shows the number of SMS per recipient and flags non-GSM characters.

Example: what does a campaign cost?

Campaign cost = recipients × segments per message × $0.03.

For large volumes, the Enterprise plan offers volume-based pricing: contact the team.

How to send bulk SMS in the DRC, step by step

With Coussema, a campaign takes eight steps and no code.

1. Create your account. Signing up gives you 10 free SMS to test with.
2. Top up by Mobile Money. SMS cost $0.03 each, with no subscription.
3. Request your Sender ID. It is free and usable once approved.
4. Import your contacts. Upload an .xlsx, .csv or .txt file, one number per line in +243 format, into a group such as “Kinshasa customers”.
5. Write the message. Check the number of SMS per recipient.
6. Test. Send the message to your own number and to a colleague on another network.
7. Send or schedule. Send right away or pick a date and time.
8. Follow the SMS report (Rapport SMS). Each message has its status, such as Reçu (delivered), Envoyé (sent) or Échec (failed).

SMS API in the DRC: sending SMS from your software

From your application, you send an SMS with a POST https://api.coussema.com/v1/sms/send request, your API key and an Idempotency-Key header. A 202 Accepted response means the message has been accepted into the sending queue, not that it has been delivered.

curl -X POST https://api.coussema.com/v1/sms/send \
  -H 'Authorization: Bearer csm_live_xxxxxxxxxxxx_xxx' \
  -H 'Content-Type: application/json' \
  -H 'Idempotency-Key: 7228b5c7-cb1d-43c0-8d68-2e9f68a5fba5' \
  -d '{
    "to": "243810000000",
    "message": "Your code is 482019",
    "senderName": "MYSHOP",
    "clientReference": "order-482019"
  }'

HTTP/1.1 202 Accepted
Content-Type: application/json

{
  "success": true,
  "queued": true,
  "status": "accepted",
  "count": 1,
  "remainingQuota": 999,
  "message": {
    "id": "11111111-1111-4111-8111-111111111111",
    "clientReference": "order-482019"
  },
  "provider": { "code": "coussema", "messageId": null, "httpStatus": 202 }
}

• Keep the API key on your server, never in a mobile app or a web page. Choose the “SMS sending only” profile.
• The Idempotency-Key header is required. Use a unique value per send; after a network failure, resend the request with the same value so it counts as a retry of the same send.
• 202 does not mean delivered. Status updates come by webhook (message.delivered or message.failed) and in the SMS report; a final receipt may be missing.
• Webhooks are signed. Check the x-coussema-signature header (HMAC-SHA256) before processing an event.

The documentation includes JavaScript, Python and PHP examples: quickstart, API reference and webhooks.

Sending OTP codes by SMS

An OTP SMS should be short and in GSM-7: the code first, how long it is valid, a reminder never to share it. Track the status by webhook and let the user ask for a new code rather than resending one automatically.

Best practices for bulk SMS

An effective, compliant campaign rests on consent, a clear identity, an easy way to opt out, the right timing and a clean list.

Get recipients’ consent

The DRC’s Digital Code (Ordinance-Law No. 23/010 of 13 March 2023) bans marketing SMS to anyone who has not given prior consent (article 68). Silence is not consent, and the sender must be able to prove it.

There is an exception (article 69): a customer whose number was collected knowingly during a sale or a service can receive your offers for similar products, provided they can refuse free of charge, when the number is collected and in every message. Record when and how each number was collected.

Identify yourself and offer a way to opt out

Every marketing SMS must give a free way to stop receiving such messages and must not hide who is sending it (article 72). Give a phone or WhatsApp number, or a short link, since nobody can reply to a Sender ID.

When someone asks to stop, acknowledge the request, remove their number and keep your opt-out list up to date: the Code requires this from online suppliers (article 70), and it is good practice for everyone.

Pick the right time

The DRC has two time zones: UTC+1 in the west, including Kinshasa, and UTC+2 in the east, including Lubumbashi and Goma. A send scheduled for 8 am Kinshasa time goes out at 9 am Lubumbashi time. Avoid nights and early mornings.

Keep it short, personalise, test

Aim for a single segment, lead with the key information, add the first name or order number, and finish with a clear action. Remove numbers that keep failing, and test every new message on several networks.

Measuring results: delivery reports (DLR)

A DLR (delivery report) is the status the operator sends back after trying to deliver an SMS.

Two other statuses exist: En attente (pending), before the message leaves for the operator, and Non confirmé (unconfirmed), when no final receipt came back.

If the phone is off, the operator’s SMS centre may hold the message for its validity period and retry delivery. An expiry confirmed by the operator shows as failed; without a final receipt, delivery stays “Non confirmé” (unconfirmed).

How to choose an SMS platform in the DRC

Check seven points: coverage of Congolese operators, Sender ID, delivery reports, API, payment, price transparency and support.

With Coussema: multi-operator coverage, a free Sender ID, the status of each SMS, a documented API, Mobile Money, $0.03 per SMS with no expiry, and a team based in Kinshasa, reachable by WhatsApp and phone. See the business SMS page.