Signatures must be approved before they can be used. This topic describes the specifications for signatures. We recommend that you follow the specifications to ensure that your signature is smoothly approved.


The following table describes the signature specifications for Short Message Service (SMS).
Item Requirements
  • A signature is used to identify a company, product, or business. We recommend that you specify the real name of your application, website, or company as a signature.
  • A signature cannot be phrases, such as Customer service or Dear customer.
  • A signature cannot contain content that violates local laws or regulations, or infringes upon the legitimate rights and interests of other persons.
Length and elements A signature must be 2 to 12 characters in length. A signature can contain letters and digits, and cannot contain special characters, including spaces.
Note Languages other than Chinese and English are not supported.
Format A signature can contain only text. You do not need to add symbols, such as [], (), and []. Signatures are automatically enclosed in brackets []. For example, a signature is displayed as [Alibaba Cloud] or [ECS].


When you send your signature for approval, you must specify the source of the signature.
Source Description
Full Name or Abbreviation for Enterprise We recommend that you provide the official website URL of your enterprise.
Full Name or Abbreviation for App If you select this source, make sure that your application is available on the application store. Provide the application store URL of your application.
Full Name or Abbreviation for Website Provide the URL of your website.