Problems sending SMS in Sandbox

  • 1
  • Problem
  • Updated 2 years ago
  • Solved
Using the code below where the login works, when trying to send an SMS, I get the following exception: Parameter [from] value [**********] is invalid [Cannot find the phone number which belongs to user]

the ******** is my valid phone number.  I assume this is because the phone numbers don't exist in the sandbox?  How do I know what numbers to use in the sandbox?  I've looked in documentation but can't find anyything.

My code:

var sdk = new SDK(appKey, appSecret, apiServer, applicationName, applicationVersion);
sdk.Platform.Login(userName, extension, password, false);

var requestBody = new {
                    text = text,
                    from = new { phoneNumber = fromPhoneNumber },
                    to = new object[] { new { phoneNumber = toPhoneNumber } } };

var jsonString = JsonConvert.SerializeObject(requestBody);
var request = new RingCentral.Http.Request("/restapi/v1.0/account/~/extension/~/sms", jsonString);

var response = sdk.Platform.Post(request);
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Kevon Houghton

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  • frustrated

Posted 3 years ago

  • 1
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Benjamin Dean, Alum

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You login to the Sandbox Online Account Portal ( to see which numbers are available in your account for use.
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Kevon Houghton

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I transposed a couple numbers. Fixing that solved my issue.
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Brian Ladouceur

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can you provide me test numbers for testing in sandbox mode.?
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VB, Official Rep

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Hi @Brain,

You can use sandbox numbers provided in Developer Portal. For additional numbers, you can add  upto 4 numbers and extensions to your Sandbox Online account here:

Here is how you add numbers in the numbers to Sandbox Online account : Adding a Digital Line (KB 3136) 

Feel free to reach us out at for additional support.