Preorders for the iPhone topped two million in 24 hours, Apple said today, breaking previous records set by its predecessor.

The latest version of Apple’s smartphone is set to go on sale in the US and UK on September 21st, with Irish customers getting the phone a week later. Other countries getting the phone in the first week of its launch will be Australia, Canada, France, Germany, Hong Kong, Japan and Singapore.

Interest in Apple’s thinnest, lightest phone yet has been high following its unveiling last week. But the success has come at a costs; Apple said demand for the phone was greater than the initial supply, and some preorders would not be delivered October.

The iPhone 4S took 1 million preorders in 24 hours.

“iPhone 5 pre-orders have shattered the previous record held by iPhone 4S and the customer response to iPhone 5 has been phenomenal,” said Philip Schiller, Apple’s senior vice president of worldwide marketing.

The phone, which comes with a new A6 chip, promises faster performance and better battery life. It also comes with Apple’s newest version of its operating system, iOS 6, which includes Apple’s new mapping software, and better integration for voice assistant Siri and Facebook.