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Choosing & Registering Sender IDs

A sender ID is what recipients see in the "From" field. Choosing the right type — and registering it where required — is the single biggest lever on deliverability.

🏷️ Sender ID Types​

TypeExampleTwo-way?Best for
AlphanumericMyBankNoBranded one-way alerts, OTP
Numeric long code+2547xxxxxxxYesConversational SMS
Shortcode21234YesHigh-volume two-way, opt-in keywords

Alphanumeric IDs are 3–11 characters, letters and digits, no spaces. They cannot receive replies — use a shortcode or long code for two-way.

📡 Registering an Alphanumeric ID​

Registration is per-country and reviewed by local carriers. Submit early — approval can take days to weeks in some markets.

curl -X POST https://api.afriroute.ai/api/v1/sms/sender-ids \
  -H "Authorization: Bearer $AFRIROUTE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "sender_id": "MyBank",
    "country": "KE",
    "use_case": "Transactional OTP and account alerts",
    "sample_message": "Your OTP is 123456"
  }'
const res = await fetch('https://api.afriroute.ai/api/v1/sms/sender-ids', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer $AFRIROUTE_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    sender_id: 'MyBank',
    country: 'NG',
    use_case: 'Transactional alerts'
  })
});
console.log((await res.json()).status); // pending_review

🌍 Per-Country Approval Rules​

Requirements vary widely. Plan around the strictest markets you target.

MarketAlphanumericPre-registration
🇰🇪 KenyaSupportedRequired
🇳🇬 NigeriaSupportedRequired
🇿🇦 South AfricaSupportedRecommended
🇪🇹 EthiopiaSupportedRequired
🇬🇭 GhanaSupportedRequired

Unregistered alphanumeric IDs are often overwritten with a generic shared ID or silently dropped.

✅ Choosing the Right ID​

  • One-way branded alerts / OTP → alphanumeric (MyBrand).
  • Customer conversations → shortcode or long code.
  • Marketing with opt-in keywords → shortcode (e.g. "Text JOIN to 21234").

💡 Best Practices​

  • Register before launch in every target country — don't assume coverage.
  • Keep the use case honest — mismatched content triggers blocking.
  • Use a consistent ID so recipients recognize and trust your brand.
  • Have a fallback ID for countries where yours isn't yet approved.
  • Avoid generic words like INFO or SMS — they get rejected.

⚠️ Common Rejections​

{
  "status": "rejected",
  "reason": "use_case_mismatch",
  "detail": "Registered as transactional but sample is promotional"
}

Match your registered use case to the actual traffic, and resubmit with a corrected sample.

📚 Related Resources​

Last Updated: May 2026