How is the SMS service charged?
It is important to note that having a positive balance (also known as credit, funds, or wallet balance) is necessary to send SMS messages.
Even if you are using the free plan and not subscribed to a paid plan, each SMS message you send carries a cost, and the corresponding amount will be deducted according to our international rates.
You can check the SMS Calculator, available in the Billing Section.
You can make an estimate before creating the campaign: specify any country and the volume of messages you plan to send (you can calculate any volume, with no limit).
Also, for extra safety, you will need to get a quote prior the bulk campaign submission and confirm it.
You might be interested in learning how to top-up your wallet.
You might be interested in learning what the SMS character limit and formatting is.