Standard SMS messages in Luxembourg have a limit of 160 characters when using GSM-7 encoding and 70 characters for Unicode. It's recommended to use GSM-7 for cost efficiency and optimal character usage, as concatenated messages are not supported.

You can use Twilio's SMS API. After initializing the Twilio client with your credentials, use the client.messages.create method, ensuring the recipient number is in E.164 format (+352). Include your message, sender ID, and optional parameters like status callbacks.

Two-way SMS is not directly supported through standard API providers in Luxembourg. If you need interactive messaging, consider alternatives or workarounds like separate inbound/outbound numbers.

Explicit consent is crucial. This can be written or electronic, but must be freely given, specific, informed, and unambiguous. Double opt-in is a best practice for marketing lists and you must maintain detailed consent records.

Luxembourg requires immediate responses to STOP, ARRÊT, and STOPP commands (case-insensitive) in addition to AIDE and HELP. You must honor opt-out requests within 24 hours and maintain your own suppression list.

While no strict rules exist, the recommended window is between 8:00 AM and 8:00 PM CET, avoiding Sundays and public holidays. Business days between 10:00 AM and 6:00 PM are ideal for marketing campaigns.

No, sending SMS to landline numbers isn't supported. Attempts will result in failed delivery and a specific error response (400 error code 21614) from the SMS API, without any charges to your account.

Alphanumeric sender IDs (max 11 characters) and international long codes are supported. Domestic long codes and short codes are not available. Alphanumeric sender IDs do not require pre-registration.

Keep messages concise (under 160 characters), include a clear call to action, and personalize thoughtfully. Avoid spam trigger words and ensure messages are localized for French, German, and English speakers.

The article mentions Twilio, Sinch, MessageBird, and Plivo as providers offering SMS APIs with good support for Luxembourg. Code examples are provided for each.

Providers have rate limits, so use exponential backoff for retries. For high volume, use batch APIs and consider queue implementation for large campaigns to manage throughput effectively.

Number portability is not available for SMS in Luxembourg. Messages are routed based on the original carrier assigned to the number, impacting deliverability if a user has switched networks.

Luxembourg adheres to GDPR and ePrivacy Directive rules. Obtain explicit consent for marketing messages and respect opt-out requests. The CNPD and ILR oversee data protection and telecommunications regulations, respectively.

Gambling, adult content, cryptocurrency promotions, and unauthorized financial services are restricted. Regulated industries like banking, healthcare, and insurance require specific compliance measures.

Always use the E.164 format, which starts with +352 followed by the local number. This ensures correct routing and delivery.