Wal-Mart Stores Inc.  (WMT) has announced a new program that lets customers trade in their used devices for credit towards a new phone. This trade-in service will be available at 3,600 Walmart stores and Sam’s Club outlets across the U.S. starting September 21. Walmart will reportedly be giving $300 in credit for Apple's (AAPL) iPhone 5 and $175 for the Samsung Galaxy S4 handset.

The announcement of the new iPhone 5s and iPhone 5c will have many phone users looking to upgrade their phones. Instead of holding on to an old phone, trading it in can help cut the cost of the latest iphones. 

While Walmart has just announced their trade-in program, companies like Amazon (AMZN) , Best Buy (BBY) , and Apple have already been offering this service to customers.

With so many options, choosing the right place to trade-in an old phone could get confusing. Here is quick comparison of the trade-in values of some of the most popular phones at Amazon, Best Buy, and Apple.

Amazon.com 

Verizon

APPLE IPHONE 4 16GB - $120

APPLE IPHONE 4S 16GB - $187

APPLE IPHONE 5 16GB - $349

SAMSUNG GALAXY S4 - $300

AT&T

APPLE IPHONE 4 16GB - $180

APPLE IPHONE 4S 16GB - $242

APPLE IPHONE 5 16GB - $363.75

SAMSUNG GALAXY S4 - $300

Sprint

APPLE IPHONE 4S 16GB - $187

APPLE IPHONE 5 16GB - $330.75

SAMSUNG GALAXY S4 – $150

Best Buy

Verizon

APPLE IPHONE 4 16GB - $105

APPLE IPHONE 4S 16GB - $170

APPLE IPHONE 5 16GB - $300

SAMSUNG GALAXY S4 - $310

AT&T

APPLE IPHONE 4 16GB - $145.00

APPLE IPHONE 4S 16GB - $220.00

APPLE IPHONE 5 16GB – $330.00

SAMSUNG GALAXY S4 - $310

Sprint

APPLE IPHONE 4S 16GB - $170

APPLE IPHONE 5 16GB - $300

SAMSUNG GALAXY S4 - $310

Apple 

Verizon

APPLE IPHONE 4 16GB - $80

APPLE IPHONE 4S 16GB - $160

APPLE IPHONE 5 16GB - $270

AT&T

APPLE IPHONE 4 16GB - $120

APPLE IPHONE 4S 16GB - $200

APPLE IPHONE 5 16GB - $310

Sprint

APPLE IPHONE 4S 16GB - $160

APPLE IPHONE 5 16GB - $270

These prices may vary depending on the color and condition of a phone. Additional parts and accessories, such as the original power adapter, can also increase the value of a phone.

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