There are two ways that consumers can use their prepaid debit card account to send money.
A caveat: these methods only apply to general-purpose-reloadable prepaid debit cards. I am not writing about gift cards, cards that hold store credit, or funds received as an incentive for signing up for a new service. The techniques here work for FDIC-insured accounts, including prepaid debit cards as well as other bank accounts.
First, you can send money with an add-on service that interacts with your bank account.
Venmo, Pop Money, and Cash App will let you send money from your bank account to a bank account of one of your friends. These are bank-to-bank transfers routed through a national ACH network. If you are willing to wait, they will send your money for free. These companies must pay a slight fee (less than 10 cents) to the ACH provider. As the networks charge a higher price for immediate settlement, each of those services asks the consumer to pay a modest fee for instant payments.
Google, Apple, and most of the smartphone providers have a payment service, too.
Usually, it would be next to impossible for a consumer to set up an ACH payment. Historically, banks have done the behind-the-scenes work to orchestrate these transactions. Venmo and its competitor services use application programming interfaces (“APIs”) to facilitate the communication between itself and the banks on both ends of the transaction. Venmo uses Plaid. Square Cash employs its in-house API developers.
Second, some banks have bundled money transmission services inside the overall basket-of-goods in their traditional account.
Don't expect to be able to use Zelle. At this moment, Zelle does not work with prepaid debit cards.