Apple iPhone 4You’ve already made up your mind that you’re going to upgrade to the new iPhone 5, but what are you supposed to do with your old smartphone? Sure, you could keep it around as a backup phone, but you can put some extra cash in your pocket if you sell your old iPhone instead.

After all, there’s a pretty good chance that your “backup” phone is just going to get neglected and collected dust in the back of your closet than it is actually going to be used. So, how can you make sure you get as much money as possible for your old iPhone 4, iPhone 3GS, or even iPhone 3G? There are a few places where you can sell it. Just make sure you backup your contacts and do a proper data wipe ahead of time, because you wouldn’t want identity thieves to get their hands on that information!

Friends and Family

The first and likely easiest way to sell your old iPhone is just to ask your friends and family if they’re interested. Not everyone needs to have the hottest new smartphone on the block nor can they necessarily afford to do it. Maybe they didn’t keep an old iPhone as a backup either and their current phone was lost or broken.

A good place to get started is to simply post a status update to your Facebook profile. This will reach the greatest number of friends, family and colleagues in the most expedient manner. You can also bring it up in conversation when you meet up in person.

Craigslist and Kijiji

Okay, maybe your immediate circle of contacts aren’t biting. It’s time to take to the online classifieds. One of the reasons why I recommend sites like Craigslist and Kijiji is that they are free to use. Make sure you list as much information as possible about your old iPhone, including real photos rather than stock images.

When you’re buying Apple products, you want to have some peace of mind about reliability and condition, so expect these online buyers to be the same way. Just be sure to exercise caution and meet up in a public place.

Cell Phone Trade-In Programs

Best Buy Trade-In Program

Best Buy Trade-In Program

Sometimes you list something on Craigslist and all you do is get inundated with spam. While you likely won’t get as much money, you can look into some trade-in programs to sell your old iPhone too. For example, the Best Buy Trade-In program is currently showing an estimated value of $300 for a 16GB iPhone 4S for AT&T. It’s a really simple process, but bear in mind that your actual trade-in value will vary based on condition and completeness.

Some carriers have their own trade-in programs as well, but they don’t tend to offer as much cash. Telus Mobility in Canada, for instance, is only showing a trade-in value of $200 for a 16GB iPhone 4S. An 8GB iPhone 3GS is only worth $65 in their eyes. I imagine you can fetch more than that through forums, classifieds, or Craigslist.

Sell Your Old iPhone on eBay

There are many reasons why you may choose to sell your old iPhone on eBay rather than going though a local listing. There’s more protection in place for both buyers and sellers, since the transaction is going through the eBay Marketplace and the payment is likely being processed by PayPal. Since you’re opening yourself up to a larger audience, there’s also the potential to make more money. However, you will have to deal with shipping and you will have to pay listing and transaction fees. These can quickly eat into your profits. It can also take more time for you to have cash on hand to buy your new iPhone 5.

If you do take this route, just as with a Craigslist posting, be sure to be as comprehensive with your eBay listing as possible. Post real photos, tell people to which carrier (if any) your iPhone is locked, and give a good description of the condition. People might want to know about the iOS version you have running too.

One of the great things about the iPhone is that it has the relentless ability to retain more of its value, especially when compared to some other smartphones. Even if your iPhone is a couple of years old, there’s a good chance that you’ll still get some decent coin if it’s in good shape.

Image credit: williamhook / Flickr