Apple has announced pre-orders of its iPhone 4S topped one million in a single day, surpassing the previous record of 600,000 held by the iPhone 4.

The iPhone 4S was made available for pre-order at 8am on Friday 7 October, though there were one or two teething problems with the pre-ordering system, as Macworld reported.

"We are blown away with the incredible customer response to iPhone 4S," said Philip Schiller, Apple’s senior vice president of Worldwide Product Marketing.

"The first day pre-orders for iPhone 4S have been the most for any new product that Apple has ever launched and we are thrilled that customers love iPhone 4S as much as we do."

The iPhone 4S will be available through all of Apple's 33 UK retail stores from 8am BST on Friday 14 October, as well as stores belonging to the UK's five main network operators, Best Buy, Carphone Warehouse and Phones4U.

The complete iPhone 4S buying guide

All customers buying from an Apple Store will be offered the free Personal Setup service so they can leave the store up and running.

The iPhone 4S includes a dual-core A5 processor, dual-core graphics, an 8MP camera and runs on iOS 5, Apple's latest mobile operating system with over 200 new features, and iCloud, a set of free cloud services that work seamlessly with your iPhone, iPad, iPod touch, Mac or PC to automatically and wirelessly store your content in iCloud and push it to all your devices.