Guinea-Bissau SMS Best Practices, Compliance, and Features

Guinea-Bissau SMS Market Overview

Mobile Network Operators

Guinea-Bissau's mobile market is served by three main operators:

• MTN Guinea-Bissau (MCC 632, MNC 02) – Major network provider with nationwide coverage
• Orange Bissau (MCC 632, MNC 03) – Significant market presence
• Guinetel (MCC 632, MNC 07) – National telecommunications operator

Market Conditions: Guinea-Bissau's mobile market has moderate penetration, with SMS remaining an important communication channel. The Autoridade Reguladora Nacional das Tecnologias de Informação e Comunicação (ARN) regulates the telecommunications sector. While OTT messaging apps are gaining popularity in urban areas, SMS remains crucial for business communications and notifications due to its reliability and widespread accessibility.

Phone Number Format

Guinea-Bissau phone numbers follow the E.164 international format:

• Country code: +245
• Total length: 7 digits (after country code)
• Mobile prefixes: Start with 5, 6, or 7
• Format example: +245 5XX XXXX or +245 6XX XXXX
• Landline prefixes: Start with 3 (not SMS-capable)

SMS Features and Capabilities in Guinea-Bissau

Guinea-Bissau supports basic SMS functionality with some limitations on advanced features. Plan carefully for message delivery and compliance.

Two-way SMS Support

Guinea-Bissau does not support two-way SMS due to technical limitations in network infrastructure and lack of standardized short code or long code provisioning.

Alternatives for two-way communication:

• Use web-based response forms with unique tracking codes in SMS
• Implement QR codes linking to mobile-optimized response pages
• Combine SMS notifications with mobile app push notifications
• Use missed call systems where recipients call back to registered numbers

Concatenated Messages (Segmented SMS)

Support: Yes, with some limitations based on sender ID type.

Message length rules:

• GSM-7 encoding: 160 characters per segment; concatenated messages use 153 characters per segment (7 characters reserved for segmentation headers)
• UCS-2 encoding (Unicode): 70 characters per segment; concatenated messages use 67 characters per segment
• Maximum segments: Most carriers support up to 10 segments (1,530 characters for GSM-7)

Encoding considerations: Supports both GSM-7 and UCS-2 encoding. Use UCS-2 for alphanumeric sender IDs.

Billing: Each segment is billed as a separate SMS. A 200-character message using GSM-7 encoding splits into 2 segments and is billed as 2 SMS messages.

MMS Support

Guinea-Bissau does not support MMS messages directly. MMS content automatically converts to SMS with an embedded URL link where recipients can view the multimedia content.

URL hosting details:

• Messaging service providers (e.g., Twilio, Sinch) host URLs
• Validity period: 30–90 days depending on provider
• Content is hosted on secure HTTPS endpoints
• Example format: "View your media: https://provider.com/media/abc123"

Recipient Phone Number Compatibility

Number Portability

Guinea-Bissau does not support number portability. Phone numbers remain tied to their original mobile network operators, simplifying message routing but limiting consumer flexibility.

Routing implications: The aggregator/gateway automatically routes messages based on the mobile prefix, which uniquely identifies the operator. You don't need to manually specify the carrier.

Sending SMS to Landlines

Guinea-Bissau does not support sending SMS to landline numbers. Attempts to send messages to landlines return a 400 response error (code 21614) through the API, with no message delivery and no account charges.

Number validation: To identify landline vs. mobile numbers:

• Mobile prefixes: 5, 6, 7 (e.g., +245 5XX XXXX)
• Landline prefixes: 3 (e.g., +245 3XX XXXX)
• Implement prefix validation before sending: if (number.match(/^\+2453/)) { /* reject landline */ }

SMS Compliance and Regulatory Requirements for Guinea-Bissau

The Autoridade Reguladora Nacional das Tecnologias de Informação e Comunicação (ARN) regulates SMS communications in Guinea-Bissau. Comply with local telecommunications laws including the Lei das Comunicações Electrónicas (Electronic Communications Law) and data privacy regulations when sending SMS messages.

Regulatory framework:

• Primary legislation: Lei das Comunicações Electrónicas (Electronic Communications Law)
• Regulatory authority: ARN (Autoridade Reguladora Nacional)
• Data protection: No specific GDPR-equivalent law; follow international best practices for data protection and consent management
• Penalties: Non-compliance may result in fines, service suspension, and regulatory sanctions; ARN determines specific penalty amounts case-by-case

Consent and Opt-In Requirements

Obtain explicit consent before sending any marketing or non-essential communications to subscribers in Guinea-Bissau. Best practices for consent management include:

• Maintain clear records of when and how you obtained consent
• Provide transparent information about message frequency and content
• Implement double opt-in procedures for marketing campaigns
• Store consent documentation securely for compliance purposes
• Consent retention: Maintain consent records for minimum 3 years or duration of customer relationship plus 1 year

Consent requirements by message type:

• Transactional messages (order confirmations, delivery updates, account notifications): Consent implied through terms of service; explicit opt-in not required
• Marketing messages (promotions, offers, newsletters): Explicit opt-in required with clear disclosure of message purpose
• Mixed content: If message contains both transactional and marketing content, treat as marketing and require explicit consent

HELP/STOP and Other Commands

All SMS campaigns must support standard opt-out commands including:

• STOP to unsubscribe (Portuguese: "PARAR" or "CANCELAR"; Creole: "PARA")
• HELP for assistance (Portuguese: "AJUDA" or "INFO"; Creole: "AIUDA")
• Recognize commands in both Portuguese and Creole (Kriol)
• Respond to these commands immediately and free of charge
• Keyword matching: Case-insensitive, exact match required (no partial matching)

Example response messages:

• STOP response (Portuguese): "Você foi removido da nossa lista. Não receberá mais mensagens. Reply AJUDA para assistência."
• HELP response (Portuguese): "Para parar mensagens, responda PARAR. Para mais informação: [contact details]"

Do Not Call / Do Not Disturb Registries

Guinea-Bissau does not maintain an official Do Not Call registry. Businesses should:

• Maintain their own suppression lists
• Honor opt-out requests immediately (within 24 hours maximum)
• Document all opt-out requests for compliance purposes
• Regularly clean contact lists to remove unsubscribed numbers

SMS Sending Time Restrictions and Best Practices

Guinea-Bissau observes GMT (UTC+0) year-round with no daylight saving time adjustments.

SMS sending restrictions:

• Restricted Hours: No marketing SMS between 10 PM and 6 AM local time unless the recipient has explicitly opted in to receive messages at any time (documented consent required)
• Daily Limit: Maximum of 3 marketing SMS messages per day per recipient per sender
• Best Practice: Schedule messages between 9 AM and 8 PM local time
• "Explicitly requested" definition: Written or electronic consent specifically authorizing after-hours messaging, with clear disclosure of timing; must be separate from general SMS opt-in
• Penalties: Violations may result in fines from ARN, filtering by carriers, and consumer complaints

Sender ID Options for Guinea-Bissau SMS

Alphanumeric Sender ID

Operator network capability: Supported with pre-registration required Registration requirements: Global pre-registration required; dynamic usage not supported Sender ID preservation: Yes, when properly registered Provisioning time: 3 weeks

Sender ID specifications:

• Length: 3–11 characters
• Allowed characters: A-Z, a-z, 0-9, spaces (cannot start or end with space)
• Restrictions: Cannot be all numeric; must contain at least one letter

Registration process:

1. Submit sender ID application through your SMS service provider (Twilio, Sinch, etc.)
2. Provide documentation: business registration, use case description, sample message templates
3. Provider submits to local carriers for approval
4. ARN may require additional compliance documentation
5. Approval takes 2–3 weeks; MTN network requires strict pre-approval
6. Once approved, sender ID is activated for use

Registration costs: Vary by provider; expect $50–200 USD one-time fee plus potential annual renewal fees. Contact your SMS provider for specific pricing.

Special note: MTN network only supports pre-registered alphanumeric sender IDs and rejects messages from unregistered IDs.

Long Codes

Domestic vs. International:

• Domestic long codes: Supported by operators but not available through major providers (Twilio, Sinch)
• International long codes: Supported with limitations on MTN network (may experience lower delivery rates or filtering)

Sender ID preservation: Yes, for international long codes Use cases: Recommended for transactional messages and two-factor authentication

MTN network limitations: International long codes may experience:

• Reduced delivery rates compared to registered alphanumeric IDs
• Higher filtering risk for promotional content
• Longer delivery times during peak hours

Domestic long code acquisition: Contact local carriers (MTN, Orange, Guinetel) directly for domestic long code provisioning; availability and pricing vary by operator.

Short Codes

Support: Not supported in Guinea-Bissau due to lack of short code infrastructure and regulatory framework. Use cases: N/A – use alternative sender ID types (alphanumeric IDs or long codes)

Restricted SMS Content, Industries, and Use Cases

The following content types and industries face restrictions:

• Gambling and betting services
• Adult content and services (pornography, dating services with explicit content)
• Political messaging without proper authorization from ARN
• Religious content that may be offensive or divisive
• Alcohol and tobacco products
• Unauthorized financial services (services without proper licensing from Banco Central da República da Guiné-Bissau)

Political messaging authorization: Contact ARN for political campaign messaging approval; requires registration of campaign, disclosure of funding sources, and compliance with electoral laws.

Authorized vs. unauthorized financial services:

• Authorized: Licensed banks, registered mobile money operators, approved fintech companies
• Unauthorized: Unlicensed lending, unregistered investment schemes, unauthorized money transfer services

Penalties for restricted content: Messages may be blocked by carrier filtering, accounts may be suspended by SMS providers, and ARN may impose fines or sanctions for serious violations.

Content Filtering

Known carrier filtering rules:

• Messages containing restricted keywords are automatically blocked
• URLs may trigger additional scrutiny
• High-frequency messaging patterns may be filtered

Best practices to avoid filtering:

• Avoid common spam trigger words: "FREE," "WIN," "PRIZE," "CLICK HERE," "URGENT," excessive use of caps or exclamation marks
• Use registered and approved sender IDs
• Maintain consistent sending patterns (avoid sudden spikes)
• Include clear business identification in messages
• URL policies: URL shorteners (bit.ly, tinyurl) may be blocked or flagged; use branded short domains or full URLs from recognized domains
• Appeals process: Contact your SMS service provider to investigate filtering; provider will work with carrier to review and potentially whitelist legitimate messages

Best Practices for Sending SMS in Guinea-Bissau

Messaging Strategy

• Keep messages under 160 characters when possible to avoid segmentation charges
• Include clear calls-to-action
• Identify your business in each message
• Use personalization thoughtfully to increase engagement

Message template examples:

• Order confirmation: "Olá [Nome], seu pedido #12345 foi confirmado. Entrega prevista: 2 dias. [BrandName]"
• Appointment reminder: "[BrandName]: Lembrete – Consulta amanhã às 14h. Responda C para confirmar ou R para remarcar."
• Promotional: "[BrandName]: Oferta especial! 20% desconto hoje. Mostre esta SMS na loja. PARAR para cancelar."

Sending Frequency and Timing

• Respect the 3-message daily limit per sender
• Space messages throughout the day (minimum 2–3 hours between messages)
• Avoid sending during religious holidays and observances
• Consider local business hours and customs

Guinea-Bissau religious holidays (avoid SMS marketing):

• Eid al-Fitr (end of Ramadan, dates vary)
• Eid al-Adha (Festival of Sacrifice, dates vary)
• Christmas (December 25)
• Good Friday and Easter (dates vary)
• National Heroes Day (January 20)

Localization

• Primary languages: Portuguese (official) and Kriol/Creole (widely spoken)
• Consider bilingual messages for important communications
• Use local date and time formats
• Respect cultural sensitivities in message content

Date/time formats:

• Date format: DD/MM/YYYY (e.g., 15/03/2025)
• Time format: 24-hour clock (e.g., 14:30)

Character encoding: Use UCS-2 (Unicode) encoding for Portuguese special characters (á, ã, ç, é, ê, í, ó, õ, ú) to ensure proper display. GSM-7 encoding does not render accented characters correctly.

Cultural considerations:

• Family and community values are important; emphasize collective benefits
• Direct sales approaches may be less effective than relationship-building messaging
• Respect Islamic customs and sensitivities (significant Muslim population)

Opt-Out Management

• Process opt-outs within 24 hours (best practice; no specific legal requirement mandates this timeframe, but immediate processing is strongly recommended)
• Maintain accurate opt-out records
• Provide clear opt-out instructions in messages ("Responda PARAR para cancelar")
• Confirm opt-out requests with a final confirmation message

Testing and Monitoring

• Test messages across all major carriers (MTN, Orange, Guinetel)
• Monitor delivery rates by carrier
• Track opt-out rates and patterns
• Regularly review message performance metrics

Delivery rate benchmarks for Guinea-Bissau:

• Good delivery rate: 85–95%
• Acceptable delivery rate: 75–85%
• Poor delivery rate: <75% (requires investigation)

Troubleshooting low delivery rates:

1. Verify sender ID registration status
2. Check for content filtering (test with simple transactional message)
3. Validate phone number formats and prefixes
4. Review sending patterns for spam-like behavior
5. Contact SMS provider support for carrier-specific issues
6. Test with different sender ID types (alphanumeric vs. long code)

SMS API Integration Guide for Guinea-Bissau

Twilio SMS API Implementation

Twilio provides a robust SMS API for sending messages to Guinea-Bissau. Here's how to implement it:

import { Twilio } from 'twilio';

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

// Function to send SMS to Guinea-Bissau
async function sendSMSToGuineaBissau(
  to: string,
  message: string,
  senderId: string
) {
  try {
    // Ensure proper formatting for Guinea-Bissau numbers (+245)
    const formattedNumber = to.startsWith('+245') ? to : `+245${to}`;

    const response = await client.messages.create({
      body: message,
      from: senderId, // Pre-registered alphanumeric sender ID
      to: formattedNumber,
      // Optional parameters for delivery tracking
      statusCallback: 'https://your-webhook-url.com/status'
    });

    console.log(`Message sent successfully! SID: ${response.sid}`);
    return response;
  } catch (error) {
    console.error('Error sending message:', error);
    throw error;
  }
}

Guinea-Bissau specific error handling:

// Common Twilio error codes for Guinea-Bissau
const GUINEA_BISSAU_ERROR_CODES = {
  21614: 'Invalid mobile number (landline or invalid format)',
  21408: 'Permission to send SMS not enabled for region',
  30006: 'Landline or unreachable carrier',
  30007: 'Message filtered (spam or content violation)',
  30034: 'Daily message limit exceeded'
};

async function sendWithErrorHandling(to: string, message: string, senderId: string) {
  try {
    return await sendSMSToGuineaBissau(to, message, senderId);
  } catch (error: any) {
    const errorCode = error.code;
    const errorMessage = GUINEA_BISSAU_ERROR_CODES[errorCode] || 'Unknown error';
    console.error(`Error ${errorCode}: ${errorMessage}`);

    // Implement retry logic for transient errors
    if (errorCode === 30006) {
      // Retry with exponential backoff
      await new Promise(resolve => setTimeout(resolve, 5000));
      return await sendSMSToGuineaBissau(to, message, senderId);
    }

    throw new Error(`Failed to send SMS: ${errorMessage}`);
  }
}

Pricing: Twilio pricing for Guinea-Bissau varies by operator; check Twilio pricing page for current rates (expect $0.06–0.10 USD per SMS segment).

Webhook status callback payload example:

{
  "MessageSid": "SM1234567890abcdef",
  "MessageStatus": "delivered",
  "To": "+2455551234",
  "From": "YourBrand",
  "Body": "Message content",
  "ErrorCode": null,
  "ApiVersion": "2010-04-01"
}

Sinch SMS API Implementation

Sinch offers SMS capabilities for Guinea-Bissau with their unified SDK:

import { SinchClient } from '@sinch/sdk-core';

// Initialize Sinch client
const sinchClient = new SinchClient({
  projectId: process.env.SINCH_PROJECT_ID,
  keyId: process.env.SINCH_KEY_ID,
  keySecret: process.env.SINCH_KEY_SECRET
});

// Function to send SMS using Sinch
async function sendSinchSMS(
  recipientNumber: string,
  messageText: string
) {
  try {
    const response = await sinchClient.sms.batches.send({
      sendSMSRequestBody: {
        to: [recipientNumber], // Must include country code +245
        from: "YourBrand", // Your registered sender ID
        body: messageText,
        // Optional delivery report URL
        deliveryReport: "URL"
      }
    });

    console.log('Message sent:', response);
    return response;
  } catch (error) {
    console.error('Sinch SMS Error:', error);
    throw error;
  }
}

MessageBird (Bird) SMS API

MessageBird's API implementation for Guinea-Bissau:

import { MessageBird } from 'messagebird';

// Initialize MessageBird client
const messagebird = MessageBird(process.env.MESSAGEBIRD_API_KEY);

// Function to send SMS via MessageBird
async function sendMessageBirdSMS(
  to: string,
  message: string,
  senderId: string
): Promise<any> {
  return new Promise((resolve, reject) => {
    messagebird.messages.create({
      originator: senderId,
      recipients: [to], // Must include +245 prefix
      body: message,
      // Optional parameters
      reportUrl: 'https://your-webhook-url.com/status',
      validity: 24 // Message validity in hours
    }, (err, response) => {
      if (err) {
        reject(err);
      } else {
        resolve(response);
      }
    });
  });
}

Provider comparison for Guinea-Bissau:

• Twilio: Best documentation, reliable delivery, established carrier relationships, higher pricing
• Sinch: Competitive pricing, good delivery rates, modern SDK with batch support
• MessageBird: Cost-effective for high volume, good delivery rates, straightforward API

Recommendation: Start with Twilio for reliability, then evaluate Sinch/MessageBird for cost optimization at scale.

API Rate Limits and Throughput

When sending SMS to Guinea-Bissau, consider these limitations:

• Daily Limits: Maximum 3 messages per recipient per day
• Throughput by carrier:
  • MTN Guinea-Bissau: 10–20 messages/second
  • Orange Bissau: 15–25 messages/second
  • Guinetel: 10–15 messages/second
• Batch Processing: Recommended batch size of 500 messages
• Retry Logic: Implement exponential backoff for failed messages

Best Practices for High-Volume Sending:

• Implement message queuing systems (e.g., RabbitMQ, AWS SQS, Redis Queue)
• Use batch APIs when available
• Monitor delivery rates and adjust sending speed
• Implement rate limiting in your application

Retry strategy example:

async function sendWithRetry(
  to: string,
  message: string,
  senderId: string,
  maxRetries: number = 3
) {
  let attempt = 0;
  let lastError;

  while (attempt < maxRetries) {
    try {
      return await sendSMSToGuineaBissau(to, message, senderId);
    } catch (error) {
      lastError = error;
      attempt++;

      if (attempt < maxRetries) {
        // Exponential backoff: 2^attempt seconds
        const delay = Math.pow(2, attempt) * 1000;
        await new Promise(resolve => setTimeout(resolve, delay));
      }
    }
  }

  throw new Error(`Failed after ${maxRetries} attempts: ${lastError}`);
}

Error Handling and Reporting

Common Error Scenarios:

• Invalid phone number format
• Exceeded daily message limit
• Network connectivity issues
• Sender ID registration problems

Recommended Logging Practices:

interface SMSLogEntry {
  messageId: string;
  recipient: string;
  timestamp: Date;
  status: string;
  errorCode?: string;
  retryCount?: number;
}

// Example logging function
function logSMSActivity(entry: SMSLogEntry): void {
  // Log to your preferred system (e.g., CloudWatch, DataDog)
  console.log(JSON.stringify(entry));
}

Guinea-Bissau Error Code Reference:

Error troubleshooting flowchart:

1. Is error code 21614 or 30008? → Validate phone number format and prefix
2. Is error code 30007? → Review message content and sender ID registration
3. Is error code 30034? → Check daily message count per recipient
4. Is error code 30006? → Implement retry logic with backoff
5. Other errors? → Contact SMS provider support with message SID

Summary and Resources

Key Takeaways

1. Compliance Requirements:

   • Pre-register alphanumeric sender IDs (3 weeks provisioning time)
   • Respect time restrictions (no marketing SMS between 10 PM and 6 AM GMT)
   • Maximum 3 messages per day per recipient per sender

2. Technical Considerations:

   • Always use international number format (+245)
   • Mobile prefixes: 5, 6, 7 (landlines start with 3)
   • Implement proper error handling with retry logic
   • Monitor delivery rates (target >85%)

3. Best Practices:

   • Maintain opt-out lists with PARAR/STOP keyword support
   • Use queuing for high-volume sending
   • Test regularly across carriers (MTN, Orange, Guinetel)
   • Use UCS-2 encoding for Portuguese accented characters

Getting Started with Guinea-Bissau SMS

1. Technical Setup:

   • Register with preferred SMS provider (budget ~$500–1000 initial setup)
   • Set up sender ID registration (3 weeks lead time, $50–200 fee)
   • Implement delivery tracking and webhook endpoints
   • Estimated timeline: 4–6 weeks from start to production launch

2. Compliance:

   • Review ARN regulations and Lei das Comunicações Electrónicas
   • Consult legal counsel for data protection compliance
   • Document consent processes and retention policies
   • Estimated costs: Legal review $500–2000 depending on complexity

3. Testing:

   • Verify delivery across carriers (MTN, Orange, Guinetel)
   • Test opt-out functionality (PARAR/STOP keywords)
   • Monitor delivery rates and adjust strategy
   • Testing budget: $100–300 for test messages

Estimated setup costs:

• SMS provider account setup: $0–500
• Sender ID registration: $50–200 per sender ID
• Legal/compliance review: $500–2000
• Testing and development: $100–300
• Total initial investment: $650–3000

Ongoing operational costs:

• SMS messaging: $0.06–0.10 per message segment
• Monthly provider fees: $0–50 (varies by provider and volume)
• Annual sender ID renewal: $0–100

Additional Resources

• ARN Official Website – Guinea-Bissau telecommunications regulatory authority
• ITU E.164 Number Format Standard – International phone number formatting
• SMS Provider Documentation:
  • Twilio SMS API Documentation
  • Twilio Guinea-Bissau Pricing
  • Sinch SMS API Documentation
  • MessageBird API Reference
• GSMA Mobile Connectivity Index – Market data and connectivity metrics