Chinese mobile networks have very strict regulations about the time of day and content that can be sent in messages to handsets on their networks. Messages are often randomly selected for manual review, causing delays and possibly a disruption of service. Customers regularly sending messages to China should submit SMS templates of their anticipated message content for whitelisting with local operators.
This whitelisting service is only available for transactional messaging to China, such as account-related alerts or OTP codes. Promotional or marketing-type traffic is not eligible for whitelisting to China and will be specifically targeted for blocking by Chinese carriers.
Due to the tight regulations in China, there are a number of limitations to be aware of.
Transactional message contents requirement:
- Your message templates must be transactional, rather than promotional in nature.
- Examples of transactional messaging include: OTP codes, authentication codes, and account- or service-related alerts.
- All messages - even those based on whitelisted templates - will have a short “signature” added to the beginning of each message.
- The default "signature" may vary, but is commonly [TLNET]. For example: "[TLNET] Hello Dan Smith, your Twilio PIN code is: 548291."
- In addition to template registration, we can register a personalized signature for you to replace the default one. This would typically be your business/service name or a shortened version of that name.
- Please note, if you choose to register a signature, you may be asked to provide a Chinese Business License certificate, depending on your use case and the signature you've requested.
Message volume limitations in place for whitelisted templates:
- Three (3) identical messages submitted to the same number within 24 hours will be rejected.
- Five (5) different messages submitted to the same number within 24 hours will automatically trigger a manual review, and a 24-hour delivery delay.
Message content must mirror confirmed whitelisted templates as strictly as possible.
- Even a small deviation might put traffic at risk of being flagged and delayed or even blocked.
- Any new message content formats would need to be whitelisted first before sending.
Whitelisting Request Process
Message template whitelist requests require the following information:
- The Twilio project Account SID that will be sending these messages. The Account SID starts with
AC, and can be found in the Console Project Settings page.
- The proposed message template(s) for whitelisting
- An English version / translation of the content.
- Company name
- Company website URL
- Estimated volume of messages per month
- Messaging use case description - Two-factor authentication (2FA) or one-time password (OTP) codes, account or transaction alerts, banking notifications, etc.
- (Optional - may add 2-3 weeks processing time) Your requested message "signature" which will be added in brackets to the beginning of your messages, example "[MYBIZ]"
Message template information
Your template(s) should include a way to identify the company sending the message, and should be relatively uniform from message to message (some content can differ like names, pin codes, dates/times, etc.). Here’s an example template:
Hello [Name], your temporary Twilio PIN code is: 
Once you have collected this information, please contact our Support team and submit your request. We will forward the template to our partners for registration, which usually takes 1-2 weeks unless additional information is required. Signature registration may add 2-3 weeks of additional lead time. Mobile operators may ask for additional supporting documents like a business license - especially for customers in the financial sector.