Registering for A2P 10DLC to become an authorized sender of business text messages is a requirement created by the U.S. Mobile Carriers.
Unregistered traffic will incur higher per-message rates and may make you more susceptible to scrutiny for TCPA violations, making you vulnerable for penalty fees.
The mobile providers have also indicated they will filter and/or not deliver unregistered messages at some point.
Registered per Message Fees: $0.002- 0.003 for registered SMS and $0.0035 - 0.01 for registered MMS.
Unregistered per Message Fees: Between $0.0025 - 0.004 for unregistered SMS and $0.013-$0.005 for unregistered MMS - with the added possibility of your messages not being delivered.