A roundup of everything we (think we) know about Apple’s iPhone 5S and 5C

Apple's iPhone event is finally upon us. It's been a year of rumours, speculation, rival devices, Internet fights, wish-lists, and more, but in a few short hours, the updated iPhone will be revealed and the cycle will begin anew.

Things kick off at 18:00 BST (10:00 PDT, 13:00 EST) and we’ll be following the event live, bringing you all the details as they happen. This launch will be a more intimate affair than Apple's June Worldwide Developer Conference (WWDC), which provided a sneak peek at iOS 7 and OS X Mavericks, with Apple giving the press a first glimpse at the new iPhone.

Until then, here's a rundown of the biggest rumours that have dominated the tech headlines for the past few months. Grab your Apple bingo forms and see how many you get.

Budget iPhone 5C

Rumours of a low cost iPhone have been circulating for ages, but they’ve picked up steam this year. If Apple really wants to compete against smartphone behemoth Samsung, the theory goes, it needs to branch out into emerging markets, and a lower cost iPhone might be the ticket. More recently, the "iPhone 5C" moniker has been attached to the device, with the "C" reportedly referring to the various colour options for the smartphone (and not the word "cheap").

China Mobile Deal

One market in which Apple would like to improve its returns is China, a country full of white label Android gadgets. Though the Chinese have clamoured for iPhones in the past, Apple recently saw a drop in revenue over in China. One way to fix that would be to launch the iPhone on China Mobile, the world's largest mobile carrier with 740 million subscribers. Reports of a China Mobile deal have been doing the rounds for some time, but the most recent rumour said that Apple is shipping the low cost iPhone 5C to the carrier. Apple is also hosting a separate press conference in Beijing, so stay tuned.

Gold iPhone (and grey?)

Japanese website Macotakara recently reported that Apple has developed a gold iPhone, which will be offered for its new high-end iPhone 5S in addition to the white and black options. Several photos of this gold (or champagne) smartphone have popped up online, with a variety of news outlets confirming its existence with sources. Gold is reportedly a popular colour in China, so this might be another effort to produce a device that will be popular in the region. Meanwhile, last month Apple insider Sonny Dickson published a gallery of photos on his website featuring a "grey or graphite" iPhone with black trim.

20 September launch date

As we reported last week, it seems that the iPhone 5S will likely go on sale in the UK on Friday 20 September, with the iPhone 5C to follow a week later. Over in the US, according to TmoNews, Apple will probably release the new iPhone(s) on 20 September. The blog cited "whispers" that T-Mobile is "blacking out" 20-22 September, meaning that employees cannot take any holidays during that time. Apple iPhone launches are usually a big production, so Apple and carrier stores require all hands on deck. These dates are in line with last year's iPhone launch – the iPhone 5 was unveiled on 12 September and it hit stores on 21 September in the UK and the US.

The sapphire touch

Ming-Chi Kuo, an analyst with KGI Securities, said that the smartphone will have a convex home button with a space for a fingerprint sensor. That home button will also reportedly be made of the same scratch-resistant sapphire crystal found on the lens of the iPhone 5.

All the rest

Bringing up the rear are reports about a 128GB iPhone, the lack of Siri on the low cost iPhone 5C, and improved battery life.

For more, check out What Apple has planned for the iPhone launch event, and our iPhone 5S and 5C wish-list.