Can you UNLOCK iPhone 4 on 6.1.3?

Can i UNLOCK not JAILBREAK my iPhone 4 running on 6.1.3, i saw that their was no untethered jailbreak, with redsn0w or ultrasn0w is it possible to unlock it to use on another carrier?

You can unlock your Apple I-phone 4 without jailbreaking using those softwares. To unlock it use remote unlocking service. Visit the site http://www.mobileunlocksolutions.com/apple-iphone-4/rs1wp9/ get remote unlocking service and unlock it easily. After unlock it you can use with any GSM sim card. In this jailbreaking is not necessary. You can unlock it permanently using this factory unlocking service.