Unlocking

If it's locked, you will need an active SIM card from the carrier it is locked to in order to complete the initial activation and make it to the home screen (with all the app icons), then you can remove the SIM Card. In this scenario, if you ever erase the iPhone or restore it or complete a major update, you will need to repeat the process.

If the iPhone is unlocked by the carrier through Apple (fully unlocked, not just flashed) then you can activate without a SIM and use it as an iPod Touch with no issues.

It all depends on the carrier it's locked to. If you insert a SIM card from another carrier into a locked iPhone, it will not work for cellular service or activate if you have to complete the set up or update screen again in the future.

Here's more info:

Reference: http://support.apple.com/kb/ht5014

iPhone: About unlocking

You can unlock your iPhone for use with different carriers.

Start the process to unlock your iPhone:

1. See if your carrier offers unlocking. Only your carrier can unlock your iPhone.
2. Contact your carrier and request an unlock. You might need to meet requirements to qualify for unlocking. After your carrier submits the unlocking request, it may take up to seven days.
3. After your carrier confirms that your iPhone unlock has been processed, go to the next section.

If you have a SIM card from a different carrier than your current carrier and your current carrier confirmed that your iPhone is unlocked, follow these steps:

1. Remove your SIM card and insert the new SIM card.
2. Complete the setup process.

If you don't have another SIM card you can use, follow these steps to complete the process:

1. Back up your iPhone.
2. Erase your iPhone.
3. Complete the setup assistant and restore your backup.

If you experience issues or see the following message in iTunes or on your device, follow the steps below:"The SIM card inserted in this iPhone does not appear to be supported. Only compatible SIM cards from a supported carrier may be used to activate iPhone. Please insert the SIM card that came with your iPhone or visit a supported carrier store."

1. Restore your iPhone.
2. Contact your carrier to verify that the unlock was applied in your carrier's system.

Most carriers offer free unlocking if the contract obligations for that phone have been fulfilled, but again, you will need to contact the carrier to find out this info.

Tripleh736 wrote:

I'm planning to but a locked iphone to Rogers from eb games and I plan to use it as an ipod can I just take the sim out and use it as an ipod?

Why don't you buy an iPod touch instead?

It's cheaper and there's no lock.