Alphanumeric Sender IDs display your brand name instead of a phone number across 150+ countries without dedicated number rental costs.
In Europe, Latin America, and parts of Asia, verification codes are predominantly delivered via Alphanumeric Sender IDs (such as 'GOOGLE' or 'UBER'). Replacing an unfamiliar number with your verified brand name increases user trust and speeds verification entry. However, global regulatory fragmentation requires distinct handling per destination country.
1 Technical Specifications of Alphanumeric Senders
Alphanumeric Sender IDs are defined under GSM standard 03.40. Constraints include:
- Maximum 11 characters.
- ASCII characters A-Z, a-z, 0-9, and spaces (symbols and punctuation are strictly prohibited).
- One-way communication: Recipients cannot reply to alphanumeric messages (inbound replies fail with signaling error).
2 Country Regulatory Tiers
Global carriers enforce three distinct operational models:
1. Dynamic Open Routing: Sender ID can be specified dynamically in the API payload without pre-registration (e.g. UK, Germany, Netherlands, Sweden, Australia).
2. Mandatory Pre-Registration: Carriers require signed authorization letters, business registration certificates, and sample message templates prior to whitelisting (e.g. France, UAE, Saudi Arabia, India, Singapore).
3. Strictly Prohibited: Carriers rewrite alphanumeric headers to generic short codes or local long codes (e.g. United States, Canada).
Frequently Asked Questions • OTP & 2FA Engineering
No. US tier-1 carriers do not support alphanumeric sender IDs for A2P traffic. All US commercial traffic must originate from 10DLC, toll-free, or dedicated short codes.
Because alphanumeric messages are one-way, regulations in many countries require including an opt-out URL or alternative long-code number in the body copy.