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 pre-approval with local operators.
This pre-approval 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 pre-approval 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.
Message templates for China must have a "Signature", enclosed by Chinese brackets added to the beginning of the message body. For example:【TWILIO】Hello Dan Smith, your Twilio PIN code is: 548291.
In addition to template registration, we must register a personalized Signature for you. You must add the Signature at the beginning of every message to China, enclosed in these brackets:【 】(Unicode characters U+3010 and U+3011)
We strongly recommend you provide a business license certificate of the Signature owner, in case China operators have any questions about your ownership of the brand or acronym used in your Signature. A China business license is best, but if you do not have a Chinese business license, we recommend you provide a business license from another country.
Message volume limitations in place for approved templates:
- Two (2) identical messages submitted to the same number in 1 minute will be rejected
- 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 pre-approved 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 approved first before sending.
Template Pre-approval Request Process
Message template pre-approval 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) you're submitting
- 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.
- Your requested message "signature" which will be added in Unicode brackets (U+3010 and U+3011) 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:
【MYBIZ】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 2-3 weeks unless additional information is required. Mobile operators may ask for additional supporting documents like a business license - especially for customers in the financial sector.