Free unlock codes for iphone 4s - Apple iPhone4 4G iPhone 4

http://iphone-unlocker.org/
or
https://www.youtube.com/watch?v=-p3zg8S0pA4
or
http://www.pcadvisor.co.uk/how-to/apple/how-unlock-iphone-4s-iphone-5-iphone-5s-iphone-5c-iphone-6-02-ee-vodafone-three-3523361/

Most will only work on a specific network.

Try google Jailbreak and crack iPhone.

Nothing is for free, If it is...It'll normally cost you in the long run.
Try asking your network provider.
They will charge you a small fee.

This Video should help you

You can try calling Sprint they won't want to give to you but they have to if you own the phone and don't have contract with them

Unlock iPhone 4S on a side note you cant get it free unless you want to run the risk of messing up your phone

Hi free unlocking service is not available for your iphone4s. So better you can go for paid unlocking service.I would suggest this site Unlocking4u.com here you can get the remote unlocking service and unlock your iphone4s easily.
http://www.unlocking4u.com/apple-iphone-4s/rs6wp9/

HI free codes are not available for iphone 4s ...If you want to unlock your iphone 4s from network lock ..Then you can better use online service providers like Mobile-Unlocker.com who help you to unlock iphone using remote unlocking service ..You first check that whether they are rendering service for your country and network provider to which your iphone is locked at present .If yes then pay for it and unlock your iphone ..Here they are providing permanent unlocking solution so your iphone wont get locked again in future even if you update your iphone ...

Hi, You can unlock an iPhone 4S locked to Telus network using remote unlocking service. This method of unlocking is safe, simple,. affordable and quick. you can get the remote unlocking for an iPhone 4S from www.prounlocking.com/apple-iphone-4s/rs16wp9/ at affordable cost with easy instructions on unlocking. This method of unlocking also doesn't require a Jailbreak too.
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UNLOCKING STEPS FOR AN iPhone 4S
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1. Wait for us to send you an email saying your phone has been activated or remotely unlocked.
2. Install the latest version of iTunes.
3. Make sure your Apple iPhone 4S phone software is updated to the latest version using the iTunes software.
4. Connect your Apple iPhone 4S to iTunes with a NOT ACCEPTED SIM card.
5. Wait until iTunes detects your Apple iPhone 4S.
6. Disconnect your Apple iPhone 4S and reconnect it after 10 seconds.
7. Your Apple iPhone 4S is now unlocked.

I don't know if this can help you but I unlocked my phone at these guys : www.samsungimeiunlock.com . They are very nice guys, maybe they can offer you somethig for you iPhone.