Sweden SMS Best Practices, Compliance, and Features

Sweden SMS Market Overview

Market Conditions: Sweden has a highly developed mobile market with near-universal smartphone penetration. While OTT messaging apps like WhatsApp and Facebook Messenger are popular, SMS remains a crucial channel for business communications, particularly for authentication, notifications, and marketing. The market is dominated by major operators including Telia, Tele2, and Telenor, with strong infrastructure supporting reliable message delivery.

Key SMS Features and Capabilities in Sweden

Sweden offers comprehensive SMS capabilities including two-way messaging, concatenated messages, and number portability, making it an ideal market for business messaging.

Two-way SMS Support

Two-way SMS is fully supported in Sweden with no special restrictions. This enables interactive messaging campaigns and customer service applications through SMS.

Concatenated Messages (Segmented SMS)

Support: Yes, concatenation is fully supported across Swedish networks.
Message length rules: 160 characters for GSM-7 encoding, 70 characters for UCS-2 encoding before splitting occurs.
Encoding considerations: GSM-7 supports standard Latin alphabet, while UCS-2 enables full Unicode support for special characters and non-Latin alphabets.

MMS Support

MMS messages are automatically converted to SMS with an embedded URL link. This ensures compatibility across all devices while still enabling rich media content delivery through clickable links.

Recipient Phone Number Compatibility

Number Portability

Number portability is available in Sweden, allowing users to keep their phone numbers when switching carriers. This feature does not affect SMS delivery or routing as the network infrastructure handles porting transparently.

Sending SMS to Landlines

Sending SMS to landline numbers is not supported in Sweden. Attempts to send messages to landline numbers will result in delivery failure, with the API returning a 400 response with error code 21614. These messages will not appear in logs and accounts will not be charged.

Compliance and Regulatory Guidelines for SMS in Sweden

Sweden follows strict data protection and privacy regulations under both GDPR and local telecommunications laws. The Swedish Post and Telecom Authority (PTS) oversees telecommunications regulations, while the Swedish Authority for Privacy Protection (IMY) enforces data protection rules.

Consent and Opt-In

Explicit Consent Requirements:

• Written or digital consent must be obtained before sending marketing messages
• Consent must be freely given, specific, and informed
• Purpose of messaging must be clearly stated during opt-in
• Records of consent must be maintained and easily accessible

Best Practices for Consent:

• Use double opt-in verification
• Maintain detailed consent logs including timestamp and method
• Clearly communicate the type and frequency of messages
• Provide easy access to privacy policy and terms

HELP/STOP and Other Commands

• Required Keywords: STOP, STOPP, AVSLUTA (Swedish)
• Optional Keywords: HJÄLP (Help in Swedish)
• Messages must be processed in both English and Swedish
• Confirmation of opt-out must be sent in the same language as the STOP request
• Response time should be immediate for all commands

Do Not Call / Do Not Disturb Registries

Sweden does not maintain a centralized Do Not Call registry, but businesses must:

• Maintain their own suppression lists
• Honor opt-out requests within 24 hours
• Implement proactive filtering of previously opted-out numbers
• Regular audit and update of suppression lists

Time Zone Sensitivity

Sweden observes Central European Time (CET/CEST)

• Recommended Sending Hours: 08:00 - 20:00 CET
• Avoid Sending: Sundays and public holidays
• Emergency Messages: Can be sent 24/7 if truly urgent
• Best Practice: Schedule campaigns between 10:00 - 18:00 on weekdays

Phone Numbers Options and SMS Sender Types for in Sweden

Alphanumeric Sender ID

Operator network capability: Fully supported
Registration requirements: No pre-registration required, dynamic usage allowed
Sender ID preservation: Yes, displayed as-is across all major networks
Length Limitation: Maximum 11 characters, alphanumeric only

Long Codes

Domestic vs. International:

• Domestic: Fully supported
• International: Supported with proper formatting Sender ID preservation: Yes, preserved across all networks
  Provisioning time: Immediate to 24 hours
  Use cases: Ideal for two-way communication, customer service, and transactional messages

Short Codes

Support: Available and widely supported
Provisioning time: 6-8 weeks for approval
Use cases:

• High-volume marketing campaigns
• Two-factor authentication
• Customer service
• Premium rate services

Restricted SMS Content, Industries, and Use Cases

Prohibited Content:

• Gambling and lottery (unless licensed)
• Adult content
• Illegal products/services
• Cryptocurrency promotions without proper disclaimers

Regulated Industries:

• Financial services require compliance with Finansinspektionen guidelines
• Healthcare messages must comply with patient privacy laws
• Political messages require clear party affiliation disclosure

Content Filtering

Known Carrier Filters:

• URLs must be from whitelisted domains
• Messages containing certain keywords may be blocked
• High frequency from same sender may trigger spam filters

Best Practices:

• Avoid URL shorteners
• Use approved sender IDs consistently
• Maintain regular but not excessive sending patterns
• Include clear company identification

Best Practices for Sending SMS in Sweden

Messaging Strategy

• Keep messages under 160 characters when possible
• Include clear call-to-action
• Personalize using recipient's name or relevant details
• Maintain consistent sender ID across campaigns

Sending Frequency and Timing

• Limit to 2-4 messages per month per recipient
• Respect Swedish holidays and summer vacation period (July)
• Avoid early morning and late evening sends
• Space out bulk campaigns to prevent network congestion

Localization

• Primary language: Swedish
• Consider bilingual messages (Swedish/English) for diverse audiences
• Use proper Swedish characters and formatting
• Respect cultural nuances and holidays

Opt-Out Management

• Process opt-outs in real-time
• Send confirmation of opt-out
• Maintain opt-out lists across all campaigns
• Regular audit of opt-out database

Testing and Monitoring

• Test across major carriers (Telia, Tele2, Telenor)
• Monitor delivery rates by carrier
• Track engagement metrics
• Regular testing of opt-out functionality

SMS API integrations for Sweden

Twilio

Twilio provides a robust SMS API with comprehensive support for Swedish numbers and messaging requirements.

Authentication & Setup:

• Account SID and Auth Token required
• Region-specific endpoints available for EU/Sweden
• Supports alphanumeric sender IDs

import { Twilio } from 'twilio';

// Initialize Twilio client
const client = new Twilio(
  process.env.TWILIO_ACCOUNT_SID,    // Your Account SID
  process.env.TWILIO_AUTH_TOKEN      // Your Auth Token
);

// Function to send SMS to Swedish number
async function sendSMSToSweden(
  to: string,
  message: string,
  senderId: string
): Promise<void> {
  try {
    // Ensure number is in E.164 format for Sweden (+46...)
    const formattedNumber = to.startsWith('+46') ? to : `+46${to.substring(1)}`;
    
    const response = await client.messages.create({
      body: message,
      from: senderId,         // Alphanumeric sender ID or Twilio number
      to: formattedNumber,
      // Optional parameters for delivery tracking
      statusCallback: 'https://your-webhook.com/status'
    });
    
    console.log(`Message sent successfully! SID: ${response.sid}`);
  } catch (error) {
    console.error('Error sending message:', error);
    throw error;
  }
}

Sinch

Sinch offers specialized SMS services with strong presence in Nordic markets.

Key Features:

• REST API with JSON payload
• Batch sending capabilities
• Delivery reports

import axios from 'axios';

interface SinchSMSConfig {
  apiToken: string;
  servicePlanId: string;
  senderId: string;
}

class SinchSMSClient {
  private readonly baseUrl = 'https://eu.sms.api.sinch.com/xms/v1';
  private readonly config: SinchSMSConfig;

  constructor(config: SinchSMSConfig) {
    this.config = config;
  }

  async sendSMS(to: string, message: string): Promise<void> {
    try {
      const response = await axios.post(
        `${this.baseUrl}/${this.config.servicePlanId}/batches`,
        {
          from: this.config.senderId,
          to: [to],
          body: message,
          delivery_report: 'summary'
        },
        {
          headers: {
            'Authorization': `Bearer ${this.config.apiToken}`,
            'Content-Type': 'application/json'
          }
        }
      );
      
      console.log('Message sent:', response.data.id);
    } catch (error) {
      console.error('Sinch SMS error:', error);
      throw error;
    }
  }
}

MessageBird

MessageBird provides a streamlined API with strong European coverage.

import { MessageBird } from 'messagebird';

class MessageBirdClient {
  private client: MessageBird;

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

  async sendSMS(
    to: string,
    message: string,
    originator: string
  ): Promise<void> {
    return new Promise((resolve, reject) => {
      this.client.messages.create({
        originator,
        recipients: [to],
        body: message,
        datacoding: 'auto' // Automatic handling of special characters
      }, (err, response) => {
        if (err) {
          reject(err);
          return;
        }
        resolve(response);
      });
    });
  }
}

API Rate Limits and Throughput

Rate Limits by Provider:

• Twilio: 250 messages/second (default)
• Sinch: 30 requests/second
• MessageBird: 60 messages/second

Throughput Management:

class SMSRateLimiter {
  private queue: Array<() => Promise<void>> = [];
  private processing: boolean = false;
  private readonly rateLimit: number;

  constructor(rateLimit: number = 30) {
    this.rateLimit = rateLimit;
  }

  async addToQueue(sendFunction: () => Promise<void>): Promise<void> {
    this.queue.push(sendFunction);
    if (!this.processing) {
      this.processQueue();
    }
  }

  private async processQueue(): Promise<void> {
    this.processing = true;
    
    while (this.queue.length > 0) {
      const batch = this.queue.splice(0, this.rateLimit);
      await Promise.all(batch.map(fn => fn()));
      await new Promise(resolve => setTimeout(resolve, 1000));
    }

    this.processing = false;
  }
}

Error Handling and Reporting

interface SMSError {
  code: string;
  message: string;
  timestamp: Date;
  recipient: string;
}

class SMSErrorHandler {
  private errors: SMSError[] = [];

  logError(error: SMSError): void {
    this.errors.push(error);
    console.error(`SMS Error [${error.code}]: ${error.message}`);
    
    // Implement specific error handling based on error codes
    switch (error.code) {
      case 'invalid_number':
        // Clean up invalid numbers from database
        break;
      case 'rate_limit_exceeded':
        // Implement exponential backoff
        break;
      default:
        // General error handling
    }
  }
}

Recap and Additional Resources

Key Takeaways

1. Compliance First:

   • Always obtain explicit consent
   • Implement proper opt-out handling
   • Respect sending hours (08:00-20:00 CET)

2. Technical Best Practices:

   • Use proper number formatting (+46)
   • Implement rate limiting
   • Monitor delivery reports

3. Integration Checklist:

   • Set up error handling
   • Configure delivery reports
   • Test with small batches first

Additional Resources

• Swedish Post and Telecom Authority
• Swedish Data Protection Authority
• GDPR Compliance Guidelines

Next Steps

1. Review your use case against compliance requirements
2. Select appropriate API provider based on volume needs
3. Implement proper error handling and monitoring
4. Set up testing environment with Swedish numbers
5. Develop consent management system