Fully dynamic SID is currently accepted, however, please be aware certain SID registration* (described below) will become mandatory in the near future. Additionally, SIDs contained in the MEF’s SMS SenderID Protection Registry require validation before being permitted for use. 

Phase 1 stipulates changes to Sender IDs from 12th September 2023:

1. Customers sending traffic to the UK with International numeric senders i.e anything other than "+44xxx" will be blocked. Operators may grant exceptions for some international numeric senders upon validation if it is an absolute requirement, please register the numeric SID with us to make this request.
2. Customers sending traffic to the UK with short code numeric senders - 5 digits starting with 6/7/8 will be permitted. All other short codes are not permitted.
3. Customers sending traffic with alpha senders with special characters i.e. senders including @, $, #, etc will be blocked. Valid special characters for an alpha/alphanumeric sender (max length of 11 digits): A to Z (Uppercase), a to z (Lowercase), 0-9 (numeric), special characters  ' ' (space), '.' (full stop), '&' (ampersand), '_' (underscore), '-' (Dash/hyphen).
4. Customers must send using their brand name, generic sender IDs such as “SMS”, “INFO” or “Alert” are not permitted.

Phase 2 stipulates changes to alpha Sender IDs and content from 31st October 2023:

1. Specific protected brands will be blocked, these brands must be whitelisted* with us alongside an LOA to ensure only valid traffic passes. Please see the list of protected brands here.
2. Variations of generic SIDs will be blocked, but not SIDs using a generic SID as a wildcard. For example, for the generic SID 'Bank' the senders 'BANK', 'bank', 'b4nk', 'B4nk' will be filtered as variations. However, the SID 'BloodBank' will still be permitted due to its use as a wildcard. Please alter any non-compliant SID to represent the brand of the traffic, to avoid any disruption of service by October 31st.

Numeric sender IDs are supported:

• LVNs with 44xxxx - 12 digits in length.
• Short Code in the legitimate format (please check phase 1 update for the details) OR any approved exception Short Code sender ID with restricted digits.

LVNs can also be purchased here Vonage's 2-way service.