LOS ANGELES » Excited about the new iPhone expected to be unveiled Sept. 10? Apple will now join others in allowing you to trade in your old model.

The company said starting today that it would give customers credit for functioning older models at Apple Stores. The credit can be used toward the purchase of a new iPhone, which will be activated in the store.

It didn’t say how much older phones would be worth. But other brokers such as Gazelle.com offer anywhere from $10 for a working iPhone 3G to $350 for an iPhone 5 that is in pristine condition.

Similar trade-in programs are run by retailers including Best Buy, Target and Radio Shack.