Apple is now allowing manufacturers to produce their own fast-charging USB-C to Lightning cables, with releases for consumers possible as early as February according to documentation from socket part suppliers.
Lighting C94 connector | ChargeLab
Eligible manufacturers that are apart of Apple's Made for iPhone program were notified at the end of November about the changes, with the required Lightning connectors now available to order. Compared to the standard USB-A Lightning cables, the new USB-C Lightning cables require a new Lightning connector, likely due to the faster 18W fast charging that they support.
New MFi guidelines | ChargeLab
Manufacturers can purchase the updated C94 Lightning Connector from Apple for $2.88 a pop, with six weeks as the estimated shipping time. That means the earliest cables could hit the market would be February.
Popular third-party accessory makers will likely be racing to be the first to market. We should see offerings from many known cable makers such as Nomad, Anker, Audrey, Native Union, and Belkin, though none have confirmed their plans as of yet.
Some manufacturers were notified earlier this year about Apple's plans to introduce third-party USB-C Lightning cables. Until Tuesday's information, though, it wasn't clear when they would actually be able to do so.
To date, anyone looking to take advantage of fast charging on the iPhone -- or quicker charging on their iPads -- needed to use Apple's USB-C Lightning cables. Apple charges $19 for a meter-long cable and $35 for the two meter.
The leaked MFi documentation was provided to MacRumors by Hong Kong site ChargeLab.