How to Tell if an iPhone Is Unlocked Without a SIM Card
The iPhone has an optional security measure that locks the phone with a four-digit passcode. After a period of idleness that can be determined by the user, this passcode must be entered when the "Home" button is pressed to activate the phone. Although the phone needs a working, valid SIM card to make calls, send texts and access the wireless Internet, you can unlock your phone with your passcode and access any installed apps that do not require the Internet.
Press the iPhone's "Home" button or "Power" button to activate the device. The screen will display a clock and your wallpaper.
Slide the onscreen arrow to the right. If the phone loads the main menu, it is currently unlocked.
Enter the iPhone's four-digit passcode (if prompted). This will unlock the phone and allow you to access many of the apps, even if your SIM card is damaged or not installed.