Square will challenge PayPal with its own peer-to-peer cash service

PayPal(s ebay) may be taking on Square on its home mobile payments turf, but Square figures two can play that game. It has its own peer-to-peer payments in the works that will let users to transfer cash to each other by simply hitting the send button on an email.

A splash page first spotted by TechCrunch on Square’s website shows a demo of the service, which for now is available only to invited users. The demo shows that a registered user only has to send an email to the payment recipient with the dollar amount of the transfer in the subject line and [email protected] in the CC field to complete a transaction. According to the page, you can email money to any debit card. An accompanying FAQ reveals that all transactions will cost the sender 50 cents a pop, but the recipient pays nothing.

We reached out to Square to get more details on the mysterious service, but the company isn’t revealing any more details for now. “We’re excited to share Square Cash with our friends,” a Square spokesperson said via email. “We’ll continue to invite others to try it out in the coming weeks.”

Of course, Square is a bit late to the party given that PayPal has dominated this space for a decade, while other companies like Braintree’s Venmo have been filling whatever gaps PayPal left in mobile peer-to-peer payments. The major banks all have their own email transfer services, and just last week at I/O, Google(s goog) announced its intention to dive head first into the same market by adding Google Wallet support to Gmail. Square might just be another peer-to-peer payments setup, but it’s building up a consumer following thanks to Square Wallet (and Starbucks(s sbux), which will help it distinguish its cash service form others.

Speaking of Google, the search giant revealed a sunset date of Nov. 20 for Google Checkout, a service it’s been promising to shut down for two years. Google has long intended to fold Checkout’s on-screen instant payment technology into Wallet. Google finally announced that transition at I/O last week.

In a blog post, Google said it would continue to support U.S. merchants that have their own payment processing technology with its new Wallet Instant Buy system. For customers who don’t have their own payment processing, Google is working with Braintree, Shopify and Freshbooks to get them up and running on new a new commerce platform.