Using alphanumeric sender IDs for SMS in the United Kingdom

An Alphanumeric Sender ID (AID) is a sender identifier that replaces a numeric phone number when an SMS is delivered to a mobile device. Instead of a long code, recipients see a branded sender name, such as a company or service name.

An AID can contain up to 11 characters, must include at least one letter, and can only contain letters and numbers (no special characters or spaces). AIDs are one-way only, meaning recipients cannot reply directly to the SMS. If replies are needed, they must be handled through other channels.

AIDs are commonly used for alerts, authentication codes, notifications, and approved marketing communications.

Requirements for the United Kingdom Alphanumeric ID registration

• Account owner or admin privileges
• A license for the product you want to manage in Number Management:
  • Zoom Contact Center license
• United Kingdom (UK) alphanumeric Sender ID (AID) requirements:
  • Approval requirement: All Alphanumeric Sender IDs (AIDs) must be approved by mobile network operators before use to prevent SMS spoofing and ensure compliance with local regulations.
  • Pre-send authorization: SMS messages cannot be sent until the AID has received operator approval.
  • Use case association: Each AID must be tied to a specific use case and SMS content type.
  • Operator authorization: Explicit authorization from the operator is required to use each AID.
  • Multiple AIDs: Businesses may register multiple AIDs, with each one undergoing a separate registration and approval process.

How to register a UK Alphanumeric Sender ID

Prepare required documentation

You will need the following information for the Business registration:

• Legal business name
• Company registration number
• Business address
• Company website

Create your business registration for the UK market

1. Sign in to the Zoom web portal as an admin with privileges to edit account settings.
2. In the navigation menu, click Number Management, then SMS Setup.
3. Click Add country/region, then select United Kingdom (UK).
4. Create your business registration for the UK market.
   • Business registration does not have a separate approval process. It is validated during the AID approval request.
     Note: Information under business registration can be updated at any time unless the SMS registration associated with this business is in pending or in active status.
5. Create and submit the AID approval request. Provide the following details:
   • Alphanumeric ID
     • Maximum 11 characters (letters and numbers only)
     • Must contain at least one letter
     • No special characters or spaces allowed
     • Case-insensitive (displayed as uppercase)
     • The required AID works only in the country where registered. Messages sent internationally may fail.
   • Usage purpose
     • Transactional: One-time passwords, two-factor authentication, account notifications, order or booking confirmations, or similar non-promotional messages.
     • Promotional: Any form of marketing or advertising.
   • SMS examples
     • Provide sample messages for review.
   • Opt-out message (for Marketing AIDs)
     • If used for marketing, include an opt-out message so Zoom can append it automatically.
     • If using a third-party system to send SMS via API, ensure the opt-out message is correctly configured.
   • Letter of Authorization (LOA)
     • Download, complete, and upload the signed LOA.
6. Submit for approval.
   • Approval may take up to two weeks for protected AIDs.

Note: If the verification team identifies missing information, you will receive an email with the operator’s failure rules and correction instructions.

Guidelines for SMS configuration and use

Content considerations

SMS messaging should be used in a manner consistent with applicable laws and regulations, including UK GDPR and the Privacy and Electronic Communications Regulations (PECR).

• Transactional Messages (typically no opt-out required):
  Examples include one-time passwords (OTPs), authentication codes, fraud alerts, service outages, delivery notifications, account security updates, and order confirmations.
  • Must relate to an existing service relationship.
  • Must not contain promotional or upsell content.
• Marketing Messages (opt-in + opt-out required):
  Promotions, discounts, product launches, cross-sell/upsell, re-engagement campaigns, and event invites.
  • Require a previous explicit opt-in consent.
  • Must include a clear opt-out mechanism.

Note: If a message contains any promotional element, it is treated as marketing. For example, “Your booking was successful. Upgrade to Premium for 20% off.”

Manage consent

• Obtain express consent before sending marketing SMS.
• Disclose the nature of messages at the time of opt-in and AID registration.
• Provide an alternative opt-out mechanism (e.g., web-based unsubscribe link, email address, account preference center, or customer support phone line).
• Process opt-out requests promptly and ensure unsubscribed recipients no longer receive messages. Acceptable opt-out mechanisms for marketing SMS include web-based unsubscribe link, email address opt-out, account preference center, and customer support phone line.
• Maintain records sufficient to demonstrate that valid opt-in consent was obtained and be able to produce those records upon request.

If Zoom, the operator, or a regulator identifies spam, content deviation, or fraud, the AID may be suspended without warning.

Avoid AID rejection or suspension

• Use a recognizable brand name or service identifier as your AID.
• Keep the AID consistent across messages of the same type.
• Register multiple AIDs if sending different types of content.
• Include clear and actionable opt-out instructions in marketing messages.
• Non-approved AIDs may be blocked or replaced with a generic numeric Sender ID by UK mobile operators.

Configuration considerations

• Use a recognizable brand name for trust and consistency.
• Keep sender IDs aligned with message type.
• Register separate AIDs for transactional and promotional content.
• Ensure opt-out mechanisms are functional and accessible