A customer uses his new iPhone 4S after making the purchase at Apple's flagship retail store in San Francisco
A customer uses his new iPhone 4S after making the purchase at Apple's flagship retail store in San Francisco, California October 14, 2011. REUTERS

With rumors swirling that the next generation iPhone will have a Sept. 12 release date and hit stores on Sept. 21, many are wondering what they can do with their old iPhone or recently purchased iPhone. But Gazelle, one of the nation's largest consumer electronics trade-in site, has the answer.

According to an announcement from the Boston-based company on Monday, Gazelle will extend its iPhone buyback deal with the current August price locked in until October so that consumers can take advantage of the highly anticipated new iPhone.

With the buyback under a price lock, consumers can elect to trade in their iPhone with Gazelle up until Aug. 31. After that, they have until Oct. 1, well after the alleged release date of the next generation model, to send their old iPhone to Gazelle.

Gazelle CMO Sarah Welcome said the extended deal will allow customers to get the most for their old iPhone in cash before the new one launches and so that they aren't without a phone.

"The majority of consumers aren't comfortable being without a phone for any amount of time," Welch said in a press release. "But the value of used devices tends to be significantly higher before a new iPhone launches. This promotion allows consumers to lock in today's value and keep their current phone until they have the new one in hand."

"The main reason was to benefit our customers," Gazelle Chief Gadget Officer Anthony Scarsella told the Los Angeles Times. "We wanted our customers to be able to lock in their price early, get a great value, but at the same time we did not want them to be without their phone."

So how exactly does a customer go about trading in their old iPhone?

1. Go to Gazelle.com

2. Select "iPhone"

3. Describe the model, carrier and condition of the used phone

After that, Gazelle said it will "quote you a price and send you shipping materials for free." If the used iPhone is received by Oct. 1, Gazelle will send the customer cash in exchange.

The best part is that Gazelle customers are not obligated to follow through with sending their old iPhone if the alleged release date isn't Sept. 21.

"Consumers are under no obligation to send in their phone, so if predictions of the new iPhone launch date turn out to be wrong, there's no risk to the consumer," the company said.

According to their website, Gazelle offers $260 for a 16GB iPhone 4S in good condition and about $160 for a 16GB iPhone 4 also in good condition.