You can update to iOS 7 without using a UDID and a developer account, but you will need to download iOS 7 ipsw file before you can do it. This was revealed by a visitor on iClarified, he did it and them the guys at iClarified also verified the same and they updated to iOS 7 without UDID and developer account.
Although it seems strange that why Apple server is allowing this kind of unauthorized update to iOS 7 but this is done and you can also try this.
You should make backup and remember you will lose any jailbreak if you have.
This version of iOS 7 is compatible for installation on development devices registered with Apple’s Developer Program. If you will try to install this iOS 7 in any unauthorized manner that could put your device in an unusable state, which could necessitate an out of warranty repair.
IOS 7 DOWNLOAD, INSTALL, LINKS, HOW TO
How to Update to iOS 7 Download. IOS 7 most advanced mobile OS. With its easy-to-use interface, amazing features, and rock-solid stability, iOS 7 is the foundation of iPhone. And even as others try to catch up, the technologies and features built into iOS 7 keep iPhone years ahead.
iOS 7 Beta 1 Download Links (Direct links from Mega):
iPad: coming soon.
- iPhone 5 (Model A1428) [Mirror]
- iPhone 5 (Model A1429) [Mirror]
- iPhone 4S [Mirror]
- iPhone 4 (GSM Rev A) [Mirror]
- iPhone 4 (GSM) [Mirror]
- iPhone 4 (CDMA) [Mirror]
- iPod touch (5th generation) [Mirror]
This is a pre-release version of iOS 7 beta for iPhone and iPod touch. Devices updated to iOS 7 beta can not be restored to earlier versions of iOS.
All you need to do is download iOS 7 ipsw file, then open iTunes connect your device and select the option of Update while pressing and holding Shit/Option button, select iOS7 ipsw firmware file and let the process complete and your device is now having iOS 7 installed.