A Twilio Account SID is a 34-character alphanumeric identifier that begins with the letters “AC" and can be found on the dashboard when logging into the Twilio Console. It is a unique key that is used to identify a specific Twilio Parent Account or Subaccount and is a credential that acts as a username.
Where to find your Twilio Account SID on a Parent Account
A Twilio Account SID can be found on the Twilio Console dashboard under Account Info as shown below:
Where to find your Twilio Account SID on a Subaccount
Alternatively, you can find the Account SID of a Subaccount by clicking on the drop-down box next to your account name as shown below.
From there select View Subaccounts in the drop-down list.
Then select the respective Subaccount you're searching for on the next page.
Once selected you'll be taken to that Subaccounts dashboard which will look relatively the same as the Parent Accounts dashboard. You can find the Subaccount Account info at the bottom of that page.
View your Parent Account SID and Subaccount SID(s) via the REST API
You can also gather your Parent Account SID and all Subaccount SID(s) via the REST API. Listed below is a doc that goes over how to gather that information in our various programming languages.
Below is a sample curl on how to gather than information from the CLI:
curl -X GET "https://api.twilio.com/2010-04-01/Accounts.json?PageSize=20" \
*Please note - it’s very important to keep your Account SID and Auth Token hidden. Do not commit it anywhere, as someone can access your full project if they have your Account SID and Auth Token (which acts as a username & password) shown above.