Tanzania SMS Guide - sms-compliance -

Tanzania SMS Best Practices, Compliance, and Features

Tanzania SMS Market Overview

Locale name:Tanzania
ISO code:TZ
RegionMiddle East & Africa
Mobile country code (MCC)640
Dialing Code+255

Market Conditions: Tanzania has a vibrant mobile communications market with several major operators including Vodacom, Airtel, Tigo, and Halotel. SMS remains a crucial communication channel, particularly for business messaging and notifications, despite growing adoption of OTT messaging apps like WhatsApp. Android devices dominate the market, accounting for over 80% of mobile devices, with iOS having limited penetration. The market shows strong growth in mobile money services, making SMS essential for financial notifications and authentication.

Key SMS Features and Capabilities in Tanzania

Tanzania supports most standard SMS features including concatenated messaging and number portability, though two-way SMS functionality is limited and MMS requires conversion to SMS with URL links.

Two-way SMS Support

Two-way SMS is not supported in Tanzania through standard channels. Businesses requiring interactive messaging capabilities should consider alternative communication methods or implement one-way messaging strategies.

Concatenated Messages (Segmented SMS)

Support: Yes, concatenation is supported for most sender ID types, though support may vary by carrier.
Message length rules: Standard 160 characters per message segment using GSM-7 encoding.
Encoding considerations: Messages using GSM-7 encoding allow 160 characters, while UCS-2 encoding (for non-Latin scripts) allows 70 characters before splitting occurs.

MMS Support

MMS messages are automatically converted to SMS with an embedded URL link to the multimedia content. This ensures compatibility across all networks while allowing rich media content to be accessed by recipients through their mobile browsers.

Recipient Phone Number Compatibility

Number Portability

Number portability is available in Tanzania, allowing users to keep their phone numbers when switching between mobile operators. This feature is fully supported and doesn't significantly impact message delivery or routing.

Sending SMS to Landlines

Sending SMS to landline numbers is not supported in Tanzania. Attempts to send messages to landline numbers will result in a failed delivery and an error response (400 error code 21614) from the messaging API, with no charges applied to the sender's account.

Compliance and Regulatory Guidelines for SMS in Tanzania

The Tanzania Communications Regulatory Authority (TCRA) oversees SMS communications and has implemented specific measures to combat fraud and ensure proper message handling. All SMS traffic is recorded and monitored for compliance with local regulations.

Explicit Consent Required: You must obtain and document explicit opt-in consent before sending any marketing or non-essential communications. Best practices include:

  • Maintaining clear records of when and how consent was obtained
  • Using double opt-in processes for marketing lists
  • Providing clear terms and conditions at the point of opt-in
  • Regularly updating consent records and purging outdated permissions

HELP/STOP and Other Commands

While Tanzania doesn't mandate specific opt-out keywords, implementing standard commands is strongly recommended:

  • Support both English and Swahili versions of STOP/SIMAMA
  • Include HELP/MSAADA options for user assistance
  • Process opt-out requests within 24 hours
  • Send confirmation messages in the user's preferred language

Do Not Call / Do Not Disturb Registries

Tanzania does not maintain an official DND registry. However, businesses should:

  • Maintain their own suppression lists
  • Honor opt-out requests immediately
  • Implement internal do-not-contact databases
  • Regularly clean contact lists to remove unsubscribed numbers

Time Zone Sensitivity

Tanzania operates in East Africa Time (EAT, UTC+3). While there are no strict time restrictions:

  • Recommended sending window: 8:00 AM to 8:00 PM EAT
  • Avoid: Religious holidays, early mornings, and late evenings
  • Emergency messages: Can be sent 24/7 if truly urgent

Phone Numbers Options and SMS Sender Types for Tanzania

Alphanumeric Sender ID

Operator network capability: Supported with pre-registration
Registration requirements:

  • Pre-registration required for both international and domestic use
  • 3-4 weeks processing time
  • Documentation of business legitimacy needed

Sender ID preservation:

  • Preserved by most carriers
  • May be replaced with generic IDs on Halotel and TTCL networks

Long Codes

Domestic vs. International:

  • Domestic long codes not supported
  • International long codes supported but not recommended

Sender ID preservation: No, original sender IDs are not preserved Provisioning time: N/A Use cases: Not recommended for primary messaging strategy

Short Codes

Support: Not currently supported in Tanzania Provisioning time: N/A Use cases: Not applicable

Restricted SMS Content, Industries, and Use Cases

Restricted Industries and Content:

  • Gambling and betting services
  • Adult content or services
  • Unauthorized financial services
  • Political messaging without proper authorization
  • Cryptocurrency promotions

Content Filtering

Known Carrier Filters:

  • Messages with unregistered sender IDs face increased filtering
  • Generic sender IDs (e.g., "INFO", "SMS") often blocked
  • URLs from unknown domains may trigger spam filters

Best Practices to Avoid Filtering:

  • Use registered sender IDs
  • Avoid excessive punctuation and all-caps
  • Keep URLs to a minimum
  • Use consistent sending patterns

Best Practices for Sending SMS in Tanzania

Messaging Strategy

  • Keep messages under 160 characters when possible
  • Include clear call-to-actions
  • Personalize messages with recipient names
  • Maintain consistent branding

Sending Frequency and Timing

  • Limit to 2-3 messages per week per recipient
  • Respect Ramadan and other religious observances
  • Avoid sending during major national holidays
  • Space out bulk campaigns to prevent network congestion

Localization

  • Support both Swahili and English
  • Use proper character encoding for Swahili diacritics
  • Consider regional dialects for targeted campaigns
  • Test message rendering on various device types

Opt-Out Management

  • Process opt-outs within 24 hours
  • Send opt-out confirmation messages
  • Maintain centralized opt-out database
  • Regular audit of opt-out compliance

Testing and Monitoring

  • Test across all major carriers (Vodacom, Airtel, Tigo)
  • Monitor delivery rates by carrier
  • Track engagement metrics
  • Regular testing of opt-out functionality

SMS API Integrations for Tanzania

Twilio

Twilio provides robust SMS capabilities for Tanzania through their REST API. Authentication uses account SID and auth token credentials.

import { Twilio } from 'twilio';

// Initialize client with your credentials
const client = new Twilio(
  process.env.TWILIO_ACCOUNT_SID,
  process.env.TWILIO_AUTH_TOKEN
);

async function sendSMSTanzania() {
  try {
    // Send message with registered alphanumeric sender ID
    const message = await client.messages.create({
      body: 'Your message in English or Swahili',
      from: 'YourBrand', // Pre-registered sender ID
      to: '+255123456789', // Tanzania number format
      // Optional parameters for delivery tracking
      statusCallback: 'https://your-webhook.com/status'
    });
    
    console.log(`Message sent successfully: ${message.sid}`);
    return message;
  } catch (error) {
    console.error('Error sending message:', error);
    throw error;
  }
}

Sinch

Sinch requires service plan ID and API token for authentication. Their API supports Tanzania's specific requirements for sender IDs.

import axios from 'axios';

async function sendSinchSMS() {
  const SINCH_BASE_URL = 'https://sms.api.sinch.com/xms/v1';
  const SERVICE_PLAN_ID = 'your_service_plan_id';
  const API_TOKEN = 'your_api_token';

  try {
    const response = await axios.post(
      `${SINCH_BASE_URL}/${SERVICE_PLAN_ID}/batches`,
      {
        from: 'YourBrand', // Pre-registered sender ID
        to: ['+255123456789'],
        body: 'Your message content',
        // Optional delivery report URL
        delivery_report_url: 'https://your-webhook.com/delivery'
      },
      {
        headers: {
          'Authorization': `Bearer ${API_TOKEN}`,
          'Content-Type': 'application/json'
        }
      }
    );
    
    console.log('Message sent:', response.data.id);
    return response.data;
  } catch (error) {
    console.error('Sinch SMS Error:', error.response?.data || error);
    throw error;
  }
}

Bird

Bird's API requires workspace ID and access key for authentication. Their service supports Tanzania's messaging requirements.

import axios from 'axios';

async function sendBirdSMS() {
  const WORKSPACE_ID = 'your_workspace_id';
  const ACCESS_KEY = 'your_access_key';
  
  try {
    const response = await axios.post(
      `https://api.bird.com/workspaces/${WORKSPACE_ID}/messages`,
      {
        receiver: {
          contacts: [{
            identifierValue: '+255123456789'
          }]
        },
        body: {
          type: 'text',
          text: {
            text: 'Your message content'
          }
        },
        sender_id: 'YourBrand' // Pre-registered sender ID
      },
      {
        headers: {
          'Authorization': `AccessKey ${ACCESS_KEY}`,
          'Content-Type': 'application/json'
        }
      }
    );
    
    console.log('Message sent:', response.data.messageId);
    return response.data;
  } catch (error) {
    console.error('Bird SMS Error:', error.response?.data || error);
    throw error;
  }
}

API Rate Limits and Throughput

  • Default rate limits vary by provider (typically 1-10 messages per second)
  • Implement exponential backoff for retry logic
  • Use batch APIs for bulk sending
  • Consider queue systems like Redis or RabbitMQ for high volume

Error Handling and Reporting

// Common error handling implementation
interface SMSError {
  code: string;
  message: string;
  timestamp: Date;
  recipient: string;
}

class SMSLogger {
  static logError(error: SMSError) {
    // Log to your preferred monitoring system
    console.error(`SMS Error [${error.code}]: ${error.message}`, {
      recipient: error.recipient,
      timestamp: error.timestamp
    });
    
    // Implement specific handling based on error codes
    switch(error.code) {
      case 'invalid_number':
        // Clean up invalid numbers from your database
        break;
      case 'network_error':
        // Queue for retry
        break;
      case 'sender_id_invalid':
        // Alert operations team
        break;
    }
  }
}

Recap and Additional Resources

Key Takeaways

  1. Compliance Priorities

    • Pre-register all sender IDs
    • Maintain proper consent records
    • Honor opt-outs immediately

  2. Technical Considerations

    • Implement proper error handling
    • Monitor delivery rates
    • Use appropriate character encoding

  3. Best Practices

    • Send during business hours (8 AM - 8 PM EAT)
    • Support both English and Swahili
    • Keep messages concise and relevant

Next Steps

  1. Review TCRA regulations at www.tcra.go.tz
  2. Register sender IDs with chosen provider
  3. Implement proper consent management system
  4. Set up monitoring and reporting

Additional Resources