Bulk SMS in Nigeria: the complete guide

What is bulk SMS?

Bulk SMS is sending one text message to many mobile numbers at once through a messaging platform or API, instead of typing it on a handset. The platform holds the recipient list, submits the message to the mobile networks and reports back what happened to each recipient.

The mechanics are the same everywhere, but the operational details are local. In Nigeria four networks carry almost all consumer traffic - MTN, Airtel, Glo and 9mobile - and each of them enforces its own rules about who may appear as the sender and which messages may reach a subscriber who has activated Do Not Disturb. Understanding those two rules explains most of what surprises people about their first campaign.

How a bulk SMS actually reaches a phone

1. 1

   You submit the message

   From a dashboard campaign or an API call. You supply the sender, the recipients in international format and the message text.

2. 2

   The platform validates and prices it

   Recipients are checked, the message is measured into pages, and the cost is calculated before anything is sent so you can see it up front.

3. 3

   It is submitted to a route

   The platform hands the message to an aggregator or gateway on either a transactional or a promotional route. The route determines which traffic the network will accept.

4. 4

   The network delivers to the handset

   The recipient's network makes the final delivery decision. A phone that is off or out of coverage is retried by the network for a period before the message expires.

5. 5

   A delivery receipt comes back

   The network returns a status per recipient. Good platforms surface it per recipient and can push it to your system as a webhook rather than making you poll.

The important consequence of this chain is that no provider controls the last step. A message can be accepted, submitted and still not be delivered because the handset was unreachable. That is why an honest platform reports the state it receives rather than promising a delivery rate.

Sender IDs: the name recipients see

A sender ID is the alphanumeric name that appears in place of a phone number when your message arrives - up to 11 characters, such as your business name. On Nigerian networks an alphanumeric sender ID must be registered before it can be used, and registration is per network.

Registration exists because the sender field is trivially spoofable, and it is the single most abused part of SMS. Networks therefore want to know which business owns which name. In practice you will be asked for the name you want, the business behind it and a description of the traffic that will carry it. Read the Sender ID registration guide for the full workflow.

Routes, DND and why some messages fail

Nigeria's Do Not Disturb service lets a subscriber block unsolicited marketing messages by texting a short code to their network. Promotional traffic to a DND-active number is blocked by the network. Transactional traffic - OTPs, alerts, service notices - travels on a different, corporate route that is not treated as marketing.

The route is not a loophole. Sending marketing copy on a transactional route is a misuse that networks act on, and it is the fastest way to lose a sender ID. The DND guide covers the register, what qualifies as transactional and how to read the failure codes.

Pages: how bulk SMS is priced

SMS is billed per page, not per message. A short message is one page; a longer message is split into several and billed for each. Multiply pages by recipients to get the cost of a campaign.

On Sendozi a page costs ₦7.00 at the same rate for transactional and promotional traffic, so a 300-character message to 1,000 recipients is two pages each: 2,000 pages. The character limits guide explains exactly where the page boundaries fall and what Nigerian-language text does to them, and the pricing guide works through costed examples.

Consent, opt-out and record keeping

Nigerian data protection law treats a phone number as personal data, so a marketing list needs a lawful basis and the people on it need a way out. Three habits cover most of it: record where each number came from and when, put an opt-out instruction in promotional messages, and act on opt-outs across every future send rather than for one campaign. The consent and compliance guide goes into what the NDPA and the NCC's consumer code actually require.

Dashboard or API?

Most teams end up using both against the same wallet and the same delivery log. If you are integrating, start with the API quickstart.

Before your first campaign

1. Register the sender ID you intend to use, and expect it to take time.
2. Normalise every number to +234 format before importing - local 0-prefixed numbers are rejected.
3. Deduplicate the list and remove anyone who has already opted out.
4. Decide honestly whether the message is transactional or promotional, and pick that route.
5. Count the characters. Know how many pages you are buying before you press send.
6. Send a test to your own numbers on at least two networks.
7. Fund the wallet for the full campaign - a send that runs out of balance stops midway.
8. Check the delivery report afterwards and record what failed and why.