Unfortunately, due to fraudulent use of the free message credit in the past, you can now only test our service by sending the standard sample message we have created. You will be able to send this pre-programmed message to multiple numbers to evaluate the serve and to see how it works.
Once you add credit to your account you are free to personalize messages as you require.
Take a look at the Sinch SMS Product page for more product information, or click here to sign up to our self-service portal and get started today.