Apple's iPhone 5, due to launch in October, will have a smaller 19-pin dock connector, replacing the 30-pin port, according to sources.
The move could have wide-ranging consequences for users and accessories manufacturers.
If Apple has switched to using a smaller 19-pin dock on the new iPhone 5, the change will hit users hard as it will make all previous accessories incompatible with the device, even if the software is capable of being updated.
Accessory manufacturers could also face expensive reconfiguring in order to produce the micro dock port and may have to remake all of their hardware to support the iPhone 5.
Reports arose after what was claimed to be a leaked picture of the forthcoming iPhone 5 (pictured), which shows a new smaller "Mini Dock" port, surfaced on website Mobile Fun.
This week, technology website TechCrunch claimed the reports had been verified by three independent manufacturers.
Apple did not respond to requests to comment.