Hungary SMS Best Practices, Compliance, and Features

Hungary SMS Market Overview

Market Conditions: Hungary has a mature mobile market with high SMS adoption rates. The three major mobile operators are Vodafone, Telenor, and Telekom, providing comprehensive network coverage across the country. While OTT messaging apps like WhatsApp and Facebook Messenger are popular, SMS remains a crucial channel for business communications, particularly for authentication and notifications. The market shows a relatively even split between Android and iOS devices, with Android having a slight edge in market share.

Key SMS Features and Capabilities in Hungary

Hungary offers comprehensive SMS capabilities including two-way messaging, concatenated messages, and number portability, though with some carrier-specific limitations on sender ID preservation.

Two-way SMS Support

Two-way SMS is fully supported in Hungary across all major carriers. There are no specific restrictions beyond standard compliance requirements for commercial messaging.

Concatenated Messages (Segmented SMS)

Support: Yes, concatenation is 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 UCS-2 encoding.
Encoding considerations: Both GSM-7 and UCS-2 encodings are supported. Messages using special characters will automatically use UCS-2 encoding, reducing the character limit per segment.

MMS Support

MMS messages are automatically converted to SMS with an embedded URL link. This ensures compatibility across all devices while still allowing rich media content to be shared. Best practice is to use short URLs and include clear context in the SMS portion of the message.

Recipient Phone Number Compatibility

Number Portability

Number portability is available in Hungary, allowing users to keep their phone numbers when switching carriers. This feature is fully supported and does not impact message delivery or routing.

Sending SMS to Landlines

Sending SMS to landline numbers is not supported in Hungary. Attempts to send messages to landline numbers will result in a failed delivery and an error response (400 error code 21614). These messages will not appear in logs and accounts will not be charged.

Compliance and Regulatory Guidelines for SMS in Hungary

As a member of the European Union, Hungary follows GDPR requirements and has specific local regulations overseen by the National Media and Infocommunications Authority (NMHH). All SMS marketing must comply with Act XLVIII of 2008 on Commercial Advertising Activities and the Hungarian Data Protection Act.

Consent and Opt-In

Explicit Consent Requirements:

• Written or electronic consent must be obtained before sending marketing messages
• Consent must be freely given, specific, and informed
• Keep detailed records of when and how consent was obtained
• Include clear terms of service and privacy policy references
• Double opt-in is recommended for marketing campaigns

HELP/STOP and Other Commands

• Must support both "STOP" and "LEIRATKOZAS" (unsubscribe in Hungarian)
• HELP/SEGITSEG commands must provide support information in Hungarian
• All automated responses should be in both Hungarian and English
• Commands must be case-insensitive and free of charge for users

Do Not Call / Do Not Disturb Registries

Hungary maintains a national Do Not Call registry ("Robinson List") managed by the NMHH.

• Businesses must check numbers against this registry before sending marketing messages
• Maintain internal suppression lists of opted-out numbers
• Process opt-out requests within 24 hours
• Regularly update and clean contact databases

Time Zone Sensitivity

Hungary observes Central European Time (CET/CEST):

• Restrict marketing messages to 8:00 AM - 8:00 PM local time
• Avoid sending during national holidays
• Emergency or service-related messages can be sent 24/7 if necessary

Phone Numbers Options and SMS Sender Types for Hungary

Alphanumeric Sender ID

Operator network capability: Partially supported
Registration requirements: Not required, but dynamic usage is supported
Sender ID preservation: Only preserved by Vodafone; Telenor and Telekom overwrite with local long code

Long Codes

Domestic vs. International: Both supported
Sender ID preservation: Yes for domestic, No for international
Provisioning time: Immediate to 24 hours
Use cases: Ideal for two-way communication, customer support, and transactional messages

Short Codes

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

Restricted SMS Content, Industries, and Use Cases

Restricted Industries and Content:

• Gambling and betting services (unless licensed)
• Adult content or services
• Unauthorized financial services
• Prescription medications
• Political messaging (requires special authorization)

Content Filtering

Known Carrier Filters:

• URLs from suspicious domains
• Keywords associated with spam or scams
• High-frequency sending patterns
• Messages containing certain special characters

Best Practices to Avoid Filtering:

• Use registered URL shorteners
• Avoid excessive punctuation
• Keep content clear and professional
• Maintain consistent sending patterns

Best Practices for Sending SMS in Hungary

Messaging Strategy

• Keep messages under 160 characters when possible
• Include clear call-to-actions
• Use personalization tokens thoughtfully
• Maintain consistent branding

Sending Frequency and Timing

• Limit to 2-4 messages per month per recipient
• Respect Hungarian holidays and observances
• Avoid weekends unless explicitly approved by recipient
• Space out bulk campaigns to prevent network congestion

Localization

• Primary language should be Hungarian
• Consider bilingual messages for international businesses
• Use proper character encoding for Hungarian special characters
• Respect cultural sensitivities and local customs

Opt-Out Management

• Process opt-outs in real-time
• Maintain centralized opt-out database
• Include clear opt-out instructions in every message
• Confirm opt-out status via confirmation message

Testing and Monitoring

• Test across all major Hungarian carriers
• Monitor delivery rates by carrier
• Track engagement metrics and opt-out rates
• Regular testing of opt-out functionality
• Monitor for carrier filtering patterns

SMS API integrations for Hungary

Twilio

Twilio provides a robust SMS API with comprehensive support for Hungarian numbers. Authentication uses account SID and auth token credentials.

import { Twilio } from 'twilio';

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

async function sendSMSToHungary(to: string, message: string) {
  try {
    // Ensure number is in E.164 format for Hungary (+36...)
    const formattedNumber = to.startsWith('+36') ? to : `+36${to}`;
    
    const response = await client.messages.create({
      body: message,
      to: formattedNumber,
      from: process.env.TWILIO_PHONE_NUMBER, // Your Twilio number
      // Optional parameters for delivery tracking
      statusCallback: 'https://your-webhook.com/status'
    });
    
    console.log(`Message sent successfully! SID: ${response.sid}`);
    return response;
  } catch (error) {
    console.error('Error sending message:', error);
    throw error;
  }
}

Sinch

Sinch offers direct carrier connections in Hungary with support for both transactional and marketing messages.

import axios from 'axios';

class SinchSMSClient {
  private readonly apiToken: string;
  private readonly serviceId: string;
  private readonly baseUrl: string = 'https://sms.api.sinch.com/xms/v1';

  constructor(apiToken: string, serviceId: string) {
    this.apiToken = apiToken;
    this.serviceId = serviceId;
  }

  async sendSMS(to: string, message: string) {
    try {
      const response = await axios.post(
        `${this.baseUrl}/${this.serviceId}/batches`,
        {
          from: 'YourCompany', // Alphanumeric sender ID
          to: [to],
          body: message,
          delivery_report: 'summary'
        },
        {
          headers: {
            'Authorization': `Bearer ${this.apiToken}`,
            'Content-Type': 'application/json'
          }
        }
      );
      
      return response.data;
    } catch (error) {
      console.error('Sinch SMS error:', error);
      throw error;
    }
  }
}

MessageBird

MessageBird provides reliable SMS delivery in Hungary with support for Unicode characters.

import { MessageBird } from 'messagebird';

class MessageBirdClient {
  private client: MessageBird;

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

  sendSMS(to: string, message: string): Promise<any> {
    return new Promise((resolve, reject) => {
      this.client.messages.create({
        originator: 'YourBrand',
        recipients: [to],
        body: message,
        type: 'sms',
        encoding: 'unicode' // Supports Hungarian special characters
      }, (err, response) => {
        if (err) {
          reject(err);
        } else {
          resolve(response);
        }
      });
    });
  }
}

Plivo

Plivo offers high-throughput SMS capabilities for the Hungarian market.

import plivo from 'plivo';

class PlivoSMSClient {
  private client: plivo.Client;

  constructor(authId: string, authToken: string) {
    this.client = new plivo.Client(authId, authToken);
  }

  async sendSMS(to: string, message: string) {
    try {
      const response = await this.client.messages.create({
        src: 'YourNumber', // Your Plivo number
        dst: to,
        text: message,
        // Optional parameters
        url: 'https://your-webhook.com/status',
        method: 'POST'
      });
      
      return response;
    } catch (error) {
      console.error('Plivo SMS error:', error);
      throw error;
    }
  }
}

API Rate Limits and Throughput

• Twilio: 100 messages per second
• Sinch: 30 messages per second
• MessageBird: 60 messages per second
• Plivo: 50 messages per second

Throughput Management Strategies:

• Implement exponential backoff for retry logic
• Use queue systems (Redis, RabbitMQ) for high-volume sending
• Batch messages when possible (max 500 per batch)
• Monitor delivery rates and adjust sending speed accordingly

Error Handling and Reporting

• Implement comprehensive logging with Winston or similar
• Track delivery receipts via webhooks
• Monitor common error codes (invalid numbers, network issues)
• Set up alerts for unusual error rates
• Store message metadata for troubleshooting

Recap and Additional Resources

Key Takeaways:

• Always format numbers in E.164 format (+36...)
• Implement proper error handling and monitoring
• Follow Hungarian time zone restrictions
• Maintain proper opt-out handling
• Use Unicode encoding for special characters

Next Steps:

1. Review NMHH regulations at www.nmhh.hu
2. Consult with local legal counsel for compliance
3. Set up test accounts with preferred SMS providers
4. Implement proper consent management
5. Establish monitoring and reporting systems

Additional Resources:

• Hungarian Data Protection Authority: www.naih.hu
• EU GDPR Guidelines: gdpr.eu
• Telecommunications Act: net.jogtar.hu
• NMHH Guidelines for Commercial Communications: [English version available on request]