Paraguay SMS Best Practices, Compliance, and Features

Paraguay SMS Market Overview

Market Conditions: Paraguay has a growing mobile market with high SMS adoption rates. The country's mobile landscape is dominated by major operators including Tigo, Personal, and Claro. While OTT messaging apps like WhatsApp are popular, SMS remains a crucial channel for business communications and notifications due to its reliability and universal reach. Android devices hold a significant market share advantage over iOS in the region.

Key SMS Features and Capabilities in Paraguay

Paraguay supports basic SMS functionality with some limitations on advanced features, focusing primarily on one-way messaging capabilities for business communications.

Two-way SMS Support

Two-way SMS is not supported in Paraguay through major SMS providers. Businesses should design their messaging strategies around one-way communications only.

Concatenated Messages (Segmented SMS)

Support: Yes, concatenated messages are supported, though availability may vary by sender ID type.
Message length rules: Standard SMS length limits apply - 160 characters for GSM-7 encoding, 70 characters for Unicode.
Encoding considerations: Both GSM-7 and UCS-2 encodings are supported, with message splitting occurring at different thresholds based on the chosen encoding.

MMS Support

MMS messages are not directly supported in Paraguay. When attempting to send MMS, messages are automatically converted to SMS with an embedded URL link where recipients can view the multimedia content. This ensures message delivery while maintaining the ability to share rich media content.

Recipient Phone Number Compatibility

Number Portability

Number portability is not available in Paraguay. This means mobile numbers remain tied to their original carriers, which can simplify message routing but may impact user flexibility.

Sending SMS to Landlines

Sending SMS to landline numbers is not supported in Paraguay. Attempts to send messages to landline numbers will result in delivery failures, with APIs typically returning a 400 response with error code 21614. These messages will not appear in logs and accounts will not be charged for failed attempts.

Compliance and Regulatory Guidelines for SMS in Paraguay

Paraguay's SMS communications are governed by Law No. 6534/2020, which includes regulations on personal data protection and cybersecurity. The National Telecommunications Commission (CONATEL) oversees telecommunications services and enforces compliance with messaging regulations.

Consent and Opt-In

Explicit Consent Requirements:

• Written or electronic consent must be obtained before sending marketing messages
• Consent records should be maintained for at least 2 years
• Purpose of messaging must be clearly stated during opt-in
• Consent language must be available in both Spanish and Guarani

Best Practices for Documentation:

• Maintain detailed records of consent acquisition method and timestamp
• Store opt-in source (web form, SMS keyword, etc.)
• Keep proof of consent messaging and terms presented to users

HELP/STOP and Other Commands

• All SMS campaigns must support standard opt-out keywords:
  • STOP, PARAR, BASTA (Spanish)
  • ANICHÉMA (Guarani)
• HELP/AYUDA messages must provide clear information about the service
• Response messages should be in the same language as the user's request
• Opt-out confirmation must be sent within 24 hours

Do Not Call / Do Not Disturb Registries

Paraguay does not maintain an official Do Not Call registry. However, businesses should:

• Maintain their own suppression lists
• Honor opt-out requests immediately
• Remove opted-out numbers within 24 hours
• Regularly clean contact lists to remove inactive numbers

Time Zone Sensitivity

Paraguay follows Paraguay Time (PYT/PYST):

• Recommended Sending Hours: 8:00 AM to 8:00 PM local time
• Urgent Messages: Can be sent outside these hours for critical notifications
• Holiday Considerations: Avoid sending on national holidays unless essential

Phone Numbers Options and SMS Sender Types for in Paraguay

Alphanumeric Sender ID

Operator network capability: Not supported
Registration requirements: N/A
Sender ID preservation: All alphanumeric IDs are overwritten with random shortcodes or local long codes

Long Codes

Domestic vs. International:

• Domestic long codes not supported
• International long codes supported but with limitations

Sender ID preservation: No, original sender ID is not preserved
Provisioning time: Immediate for international long codes
Use cases: Transactional messages, alerts, and notifications

Short Codes

Support: Available through local carriers
Provisioning time: 8-12 weeks for approval
Use cases:

• High-volume marketing campaigns
• Two-factor authentication
• Customer service communications

Restricted SMS Content, Industries, and Use Cases

Prohibited Content:

• Gambling and betting services
• Adult content or explicit material
• Unauthorized financial services
• Political campaign messages without proper authorization
• Religious content without explicit consent

Regulated Industries:

• Financial services require CONATEL approval
• Healthcare messages must comply with privacy regulations
• Educational institutions need proper accreditation

Content Filtering

Carrier Filtering Rules:

• URLs are scrutinized for malicious content
• Keywords related to restricted industries are blocked
• Multiple exclamation marks or all-caps messages may be filtered

Best Practices to Avoid Blocking:

• Avoid URL shorteners
• Use clear, professional language
• Limit special characters and symbols
• Include company name in message body

Best Practices for Sending SMS in Paraguay

Messaging Strategy

• Keep messages under 160 characters when possible
• Include clear call-to-action
• Use personalization tokens (customer name, account info)
• Maintain consistent sender identity

Sending Frequency and Timing

• Limit to 4-5 messages per month per recipient
• Respect local holidays and cultural events
• Avoid sending during siesta hours (1:00 PM - 3:00 PM)
• Space out campaign messages to prevent fatigue

Localization

• Primary languages: Spanish and Guarani
• Consider bilingual messages for wider reach
• Use local date/time formats (DD/MM/YYYY)
• Adapt content for local cultural context

Opt-Out Management

• Process opt-outs within 24 hours
• Maintain centralized opt-out database
• Confirm opt-out status via SMS
• Regular audit of opt-out list compliance

Testing and Monitoring

• Test across major carriers (Tigo, Personal, Claro)
• Monitor delivery rates by carrier
• Track engagement metrics
• Regular A/B testing of message content
• Document and analyze failure patterns

SMS API integrations for Paraguay

Twilio

Twilio provides a robust SMS API with comprehensive support for Paraguay. Integration requires account credentials and proper phone number formatting.

Key Parameters:

• Account SID and Auth Token for authentication
• From number must be a valid Twilio number
• Recipient numbers in E.164 format (+595XXXXXXXXX)

import { Twilio } from 'twilio';

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

async function sendSMSToParaguay(
  to: string,
  message: string
): Promise<void> {
  try {
    // Validate Paraguay phone number format
    if (!to.startsWith('+595')) {
      throw new Error('Invalid Paraguay phone number format');
    }

    const response = await client.messages.create({
      body: message,
      to: to,  // Example: +595981234567
      from: process.env.TWILIO_PHONE_NUMBER,
    });

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

Sinch

Sinch offers direct carrier connections in Paraguay with support for high-volume messaging.

Key Parameters:

• Service Plan ID and API Token
• Sender ID (will be overwritten with local format)
• Destination number in international format

import axios from 'axios';

interface SinchSMSResponse {
  id: string;
  status: string;
}

async function sendSinchSMS(
  to: string,
  message: string
): Promise<SinchSMSResponse> {
  const SINCH_BASE_URL = 'https://sms.api.sinch.com/xms/v1';
  const SERVICE_PLAN_ID = process.env.SINCH_SERVICE_PLAN_ID;

  try {
    const response = await axios.post(
      `${SINCH_BASE_URL}/${SERVICE_PLAN_ID}/batches`,
      {
        from: process.env.SINCH_SENDER_ID,
        to: [to],
        body: message,
      },
      {
        headers: {
          'Content-Type': 'application/json',
          Authorization: `Bearer ${process.env.SINCH_API_TOKEN}`,
        },
      }
    );

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

MessageBird

MessageBird provides reliable SMS delivery in Paraguay through their REST API.

import { MessageBird } from 'messagebird';

class MessageBirdService {
  private client: MessageBird;

  constructor(apiKey: string) {
    this.client = new MessageBird(apiKey);
  }

  async sendSMS(
    to: string,
    message: string
  ): Promise<any> {
    const params = {
      originator: 'YourBrand',
      recipients: [to],
      body: message,
      datacoding: 'auto', // Handles special characters
    };

    return new Promise((resolve, reject) => {
      this.client.messages.create(params, (err, response) => {
        if (err) {
          reject(err);
        } else {
          resolve(response);
        }
      });
    });
  }
}

Plivo

Plivo offers SMS capabilities in Paraguay with support for Unicode messages.

import * as plivo from 'plivo';

class PlivoService {
  private client: plivo.Client;

  constructor() {
    this.client = new plivo.Client(
      process.env.PLIVO_AUTH_ID,
      process.env.PLIVO_AUTH_TOKEN
    );
  }

  async sendSMS(
    to: string,
    message: string
  ): Promise<any> {
    try {
      const response = await this.client.messages.create({
        src: process.env.PLIVO_SOURCE_NUMBER,
        dst: to,
        text: message,
        url_strip_query_params: false
      });
      return response;
    } catch (error) {
      console.error('Plivo SMS Error:', error);
      throw error;
    }
  }
}

API Rate Limits and Throughput

• Default rate limit: 100 messages per second
• Batch processing recommended for volumes > 1000/hour
• Implement exponential backoff for retry logic

Throughput Management Strategies:

• Queue implementation for high-volume sending
• Message prioritization system
• Automatic rate limiting and throttling
• Batch processing with optimal chunk sizes

Error Handling and Reporting

Logging Best Practices:

• Implement structured logging with correlation IDs
• Track delivery receipts (DLRs)
• Monitor carrier responses
• Set up alerting for error thresholds

Common Error Scenarios:

• Invalid phone numbers
• Network timeouts
• Carrier rejections
• Rate limit exceeded

Recap and Additional Resources

Key Takeaways:

1. Always format numbers in E.164 format (+595XXXXXXXXX)
2. Implement proper error handling and retry logic
3. Monitor delivery rates and carrier responses
4. Follow local compliance requirements
5. Maintain opt-out lists and honor unsubscribe requests

Next Steps:

1. Review CONATEL regulations at www.conatel.gov.py
2. Consult with local legal counsel for compliance verification
3. Set up monitoring and reporting systems
4. Test thoroughly across all major carriers

Additional Resources:

• CONATEL Telecommunications Guidelines
• Paraguay Data Protection Law
• SMS Best Practices Guide
• Technical support contacts for major carriers:
  • Tigo: support@tigo.com.py
  • Personal: soporte@personal.com.py
  • Claro: ayuda@claro.com.py