How to Unlock a Straight Talk USA iPhone. Since contacting Straight Talk company and ask them to unlock your iPhone is not a cheap option, the Official IMEI Method is the only available and affordable solution. First, you need to verify that your iPhone is Locked on Straight Talk USA and find its Blacklist status! This method, will locate the IMEI number of your iPhone (It is a unique 15-digit number all iPhones have – Dial *#06# to get it) in Apple’s databases and switch its status from Locked to Unlocked.