With the iPhone 18 series approaching, a forecast says users looking to dispose of an existing iPhone may be better off speeding up a sale. The analysis says used prices for current models could fall by up to 30 percent within weeks after a new iPhone is unveiled.

Tech outlet TechRadar reported on Aug. 19 that Sam Wilson (샘 윌슨), a director at refurbished device trader GadgetGogo, expects used values of existing iPhones could fall quickly ahead of the iPhone 18 launch.

When a new product appears, demand for the previous generation typically falls and second-hand prices adjust. The explanation said the price drop could be larger for higher-priced models.

Wilson advised users who currently own an iPhone Pro or Pro Max to bring forward their selling timing. He said the device’s value could drop by 150 to 300 pounds within weeks of a new product launch, adding that selling a little earlier can make a big difference to the amount actually received.

The price drop does not apply only to the latest premium models. Relatively cheaper or older iPhones can also see their used prices affected when a new generation appears.

Past data showed sharp drops in used prices often concentrate right after a new product is officially launched. Some models, however, were seen to start falling even ahead of the new launch.

The problem is that users may have to sell their existing smartphone first when they still cannot buy the new iPhone 18. For users who need their current phone, a gap can emerge between selling and replacing.

Wilson suggested starting the selling process now if an upgrade is planned for September. Some buyback services lock in a purchase price at the current time while allowing users to keep using their existing smartphone for several weeks.

Other smartphones face similar effects, not just iPhones. A drop in used prices for the previous generation when a new flagship launches is a common phenomenon in the smartphone market. TechRadar cited Samsung Electronics’ Galaxy S26 as a case where selling before the next model’s launch could also be advantageous.

The timing of price moves differs by product. The Galaxy S27 is still some time away from launch, but the iPhone 18 series is being discussed as possibly being unveiled in early to mid-September.

The expected iPhone 18 lineup is forecast to include the iPhone 18 Pro, iPhone 18 Pro Max and iPhone Ultra. As a result, anyone planning to sell an existing iPhone and switch to a new product needs to watch used-price swings closely over the less-than-a-month period ahead.

Ultimately, if planning to buy an iPhone 18, users need to weigh not only the new model’s price and specifications but also when and how to dispose of their existing iPhone. If using a buyback firm’s price-lock service, it may be possible to keep using the current device while reducing the risk of a price drop, and use it as one selling strategy.