Before requesting spending limit increase, you need to roughly estimate how many SMS's you wish to send per month.
For example, let's say most of your users are in India where SMS costs US$ 0.00223 per message. You estimate you need to send about 50,000 SMS per month. This will cost you US$ 111.5.
So you might want to request a slightly higher spending limit, say US$ 200.
Login to your AWS Account and go to Support Center. Follow the instructions in images below to request a spending limit increase for SMS messages.
That’s it. AWS will take a few hours to respond. If AWS needs any extra information they will ask you for the same before increasing your spending limit.
Do not worry if AWS gives you a lesser limit than what you asked for. Just send a few SMS, wait for a few days and submit another limit increase request.
Over time, depending on your usage and reputation, you can continue asking AWS to increase these limits. They will do so gladly but only if your sending reputation is good. So make sure you don’t send out any spammy SMS's.
6. One Final STEP
Once AWS grants you your SMS spending limit increase, you will need to input that value in Send With SES (see below image).
If you send unsolicited SMS your account will be banned by AWS.
Send With SES will not be able to help you in this case.