Apple’s upcoming iMessage-based mobile payments service, powered by Apple Pay, won’t arrive tomorrow with the release of the new operating system for Apple’s mobile devices, iOS 11. According to an announcement released today by the company, the service will instead ship in a later release to iOS 11 and watchOS 4, due this fall.

Apple didn’t give an exact time frame for that launch, but it was already expected that the feature would not be included in the updated OS tomorrow, given that Apple’s website had already flagged the Apple Pay service as “coming this fall,” as MacRumors has pointed out.

The payments service, which will serve as Apple’s competitor to rivals like PayPal or Venmo, was first announced at Apple’s Worldwide Developer Conference in June. The company explained at the time that the feature will be built into the iMessage app, allowing users to send and request money from friends and family with a tap.

The service will also work with Siri, so you can tell Apple’s built-in virtual assistant to pay someone in order to kick off a transaction. The funds will come from users’ credit and debit cards already saved into their Apple Wallet application. And when users get paid via Apple Pay, they’ll receive the money in a new “Apple Pay Cash” card stored to Apple Wallet, making the funds available instantly.

You can choose to transfer those funds from the virtual card to your bank, if you want, but they can also remain on the card, where they can be applied to transactions both in-store and online. This is a significant move on Apple’s part, because payments companies can make money by holding users’ balances

Other payment services, including Venmo and Square Cash, already offer integrations with iMessage through their own apps, but Apple’s advantage here is the sizable user base of existing iOS device users, as well as the fact that it owns the platform, allowing for a more seamless user experience.

Apple also already has most users’ payment cards on file, as customers generally add cards to their Wallet, as well as to their Apple profile, in order download apps from the iOS App Store, or make purchases from iTunes.

Apple’s move comes at a time when there’s increased competition among mobile payments providers. In addition to PayPal, Venmo (also owned by PayPal), and Square Cash, U.S. banks have decided to get in on the action too with Zelle, a Venmo-like app that recently became available on iOS and Android offering instant bank transfers.