There is a simple reason September matters to anyone still carrying an iPhone 15 Pro Max: Apple’s next premium iPhones are close enough to change the second-hand market before they ever reach a customer’s hand.
The usual advice to ‘wait and see what Apple launches’ sounds sensible if you are undecided about upgrading. It can be less sensible if you already know you want a new phone, because the device you plan to sell is still depreciating while you wait.
A £421 phone today – but what about November?
SellMyPhone’s iPhone 15 Pro Max comparison page showed a leading working-condition offer of about £421 when checked for this article. More interestingly, its 18-month pricing model estimates that the same offer could fall by roughly £86, or around 20%, over the next three months if typical trends continue.
That forecast is not a guaranteed future price; recycler demand moves constantly. But it gives owners a concrete way to think about timing. If you are already asking whether to sell my iPhone 15 Pro Max before the next Pro launch, the potential cost of waiting is no longer abstract.
Why the iPhone 18 Pro launch is unusually important
Current reporting suggests Apple will release its iPhone 18 Pro models in autumn 2026 while delaying the standard iPhone 18 until early 2027. The Verge reports that the split launch would break Apple’s usual all-at-once September pattern.
For a 15 Pro Max owner, that means September could produce a concentrated wave of premium upgrades. Those are exactly the users most likely to put another Pro Max into the resale system.
Three things can happen at once
- Demand shifts toward Apple’s newest premium model.
- More 15 Pro and 15 Pro Max handsets enter the used market as owners upgrade.
- Recycler offers are adjusted as supply, retail discounts and second-hand demand change.
None of those effects guarantees an overnight price collapse. They do, however, explain why a phone can be worth materially less several months after a launch even when its condition has not changed.
Selling early only makes sense if you were going to upgrade anyway
This is the part launch-season advice often misses. Selling a perfectly good phone simply because a new model exists can be a terrible financial decision. The cheapest smartphone is usually the one you already own.
But if the iPhone 18 Pro Max is already on your shopping list, the relevant calculation is different. Compare the value of the 15 Pro Max today with the amount you expect to add for the new phone. Then compare that with the same calculation after launch. The new phone’s price may barely move while the old one’s value does.
What should owners do before Apple’s event?
- Check a live resale value now and save the figure as your baseline.
- Be realistic about condition – small damage can materially change recycler offers.
- Decide which iPhone 18 features would actually justify upgrading for you.
- Calculate the net upgrade cost, not just the new phone’s retail price.
SellMyPhone compares live offers from UK phone recyclers, making it possible to see the current market without accepting the first trade-in quote you are shown.
The £86 estimate is not a reason to panic-sell a phone you love. It is a reminder that timing has a price. If you already intend to upgrade this autumn, checking the 15 Pro Max’s value before Apple’s announcement gives you the one thing launch hype usually removes: options.
