What should be the signature of the sender when sending via SMS gateway? Number or letter

Question

SMS

More recently, cellular operators have banned letter signatures in order to combat spam and have forced all "SMS providers" (smsc.ru, bytehand.com, etc.) to ensure that only signed numbers are sent.
In view of this, SMS providers unanimously increased the prices for SMS, and many of their clients were forced to additionally rent a real phone. number to send.
Now there is absolutely opposite, illogical news https://www.bytehand.com/news?id=30, that now you can’t sign with a number, you have to use letters again.
Please help me understand the current situation. How right now. Sign SMS with letters or a number?

Answer 1

It seems that each SMS site provides its own features. Here, for example, www.sms16.ru you can do this and that. Checked just recently.

Answer 2

The policy there is very simple - "who paid, that and slippers."
This problem is with a megaphone and tele2. They began to fight big money for sending SMS with a letter addressee through "their trusted" gateways.