How DND works in Nigeria.

What is DND?

DND — Do Not Disturb — is a consumer-protection framework administered by the Nigerian Communications Commission (NCC). It lets Nigerian mobile users opt out of promotional SMS, short calls, and data bundle offers from their carrier by texting a short code. Every major Nigerian carrier — MTN, Airtel, Glo, 9mobile — participates.

Once a number is on the DND register, the carriers apply filtering to inbound SMS. A message classed as marketing is blocked at the carrier edge. A message classed as transactional — OTPs, order status, service updates — passes through on a separate compliant corridor.

How DND works in Nigeria

The practical flow looks like this:

1. A mobile user texts a short code (commonly 2442) to their carrier, choosing which classes of SMS to block. Options typically include "full DND" (all promotional) or narrower filters.
2. The carrier flags the number in its DND register. From then on, every inbound SMS is inspected: if it originates from a sender ID categorised as marketing, the message is rejected by the carrier before it reaches the handset.
3. Senders who want to reach DND-registered numbers for transactional purposes (OTPs, account alerts, order confirmations) route through a separately contracted DND-compliant corridor. This corridor is restricted to classes the carrier has sanctioned.

Our platform enforces this on your behalf. Every sender ID you request is approved for a set of message classes at the time of submission. When you dispatch a campaign, we route it on the corridor that matches the class — automatically.

Messages that reach DND-registered numbers

Transactional messages are allowed on DND numbers because they serve the recipient's interest: they want the OTP to log in, the order confirmation to track their package, the appointment reminder not to miss their doctor. The carrier-sanctioned classes are:

• OTP — login codes, verification codes, one-time passwords.
• Transactional — order confirmations, shipped alerts, delivery tracking, payment receipts.
• Service update — account changes, password changes, schedule shifts, outage notices.
• Reminder — appointment reminders, subscription renewals.

Messages that don't

Marketing messages — promotional, advertising, bulk discount offers — are blocked on DND-registered numbers. This includes:

• Discount codes and "% off" promotions
• New-product announcements
• Abandoned-cart and "come back" campaigns
• Loyalty offers positioned as promotions
• Event invitations when the invitation is a promotion

The carriers enforce this rule, not us. A marketing message to a DND-registered number simply doesn't arrive — and attempting it repeatedly puts your sender ID's reputation at risk.

Worked example

Say you run a small e-commerce shop with a list of 2,000 customers. 300 of them are DND-registered. You have two messages to send today:

• Allowed: "Your order #81204 is ready for pickup at our shop." — class Transactional → reaches all 2,000 via the DND corridor. Cost: 2,000 × ₦8.00 = ₦16,000.
• Blocked for 300: "Get 20% off your next order — use code MAY20." — class Marketing → reaches 1,700 non-DND numbers via the generic route. The 300 DND numbers are blocked by the carrier. Cost: 1,700 × ₦6.50 = ₦11,050.

Both are valid sends. Which one is right depends on whether your message is transactional or promotional in intent — not on which one is cheaper.

How PostAm SMS routes DND traffic

When you submit a campaign, our preflight checks the message class against the sender ID's allowed classes and against the campaign's intent. One of three things happens:

1. Marketing class, generic route — routed on the generic corridor. DND-registered numbers in your audience don't receive the message. The rest do.
2. Transactional / OTP / service-update class, DND corridor — routed on the compliant corridor. Every number in your audience is reached, DND-registered or not.
3. Marketing class, DND corridor (not allowed) — the send is blocked at preflight. You see the reason in the dashboard and can adjust the class or audience.

What this looks like in the dashboard

The DND-routing check shows as one of the eight preflight rows. It reports the route selected, why, and surfaces a warning if the combination is unusual (e.g. a marketing campaign targeting a list that has 90% DND-registered numbers — most of your audience won't receive it, so we flag it before you waste a reserve).

Promotional vs transactional

The cleanest rule we've seen operators use: "If the recipient didn't actively ask for this message, it's promotional." An OTP they asked for by logging in? Transactional. A delivery update on a package they bought? Transactional. A "come back, we miss you" offer? Promotional.

When in doubt, class the message as marketing and route generic. You'll reach most of your audience, and you won't risk a carrier complaint that affects your sender-ID reputation.