I am using aws sns for sending sms to Indian phone numbers since last two months.I am using PHP SDK for api calls.
I had sent 7000+ successful messages with custom senderid relating to our company name.But since last 4-5 days same clients/phone no.s are receiving messages with aws's default senderid "NOTICE".
I am publishing messages to a topic to send sms. Now in past few pushed messages all clients got default senderid, while in few pushed messages only few clients got default id while others got my custom id.
So, where is the problem?
If your destination phone number is in India, your Sender ID must be registered to be able to work. You can request to register a Sender ID by opening a support ticket with AWS support (which has no cost).
Other countries require no registration, thus, some deliveries will work by just adding a sender ID value to your publish request.
You might successfully get a working sender ID to an Indian destination depending on the route the message takes to reach an end user. However, the right course of action (given technology partners and provider regulations) is to register the sender ID before using it with AWS (which is why it's not marked on the website).
Disclosure: I work at the AWS team for Mobile Messaging.