The Best Time to Sell Your Old iPhone Before a New Model Drops

Timing matters enormously when it comes to getting the best price for your iPhone. Sell it at the wrong time — particularly just after Apple announces a new model — and you could receive 15–25% less than you would have a few weeks earlier. This guide explains the iPhone depreciation curve, the critical sale windows throughout the year, and the practical steps you should take to maximise your trade-in value.

The iPhone Depreciation Curve

Like all consumer electronics, iPhones lose value over time — but the depreciation is not linear. There are specific trigger points when value drops sharply:

Year 1: Minimal Depreciation

In the first six months after launch, a flagship iPhone retains most of its value — typically 75–85% of its retail price. Demand on the secondary market is strong because many people who couldn’t get the new model at launch are happy to buy second-hand. If you buy every new iPhone, this is the window where selling your previous model yields the best return.

The September Cliff

Apple holds its annual iPhone launch event every September (typically the second Tuesday of the month). The moment a new model is announced, the previous generation drops in trade-in and resale value — often by £50–£150 on flagship models overnight. This is the single most important date in the phone resale calendar. The weeks immediately before the September announcement are the highest-value window to sell your current iPhone.

Years 2–3: Steady Decline

After the first year, iPhones depreciate at a steadier rate of roughly 20–30% per year. The cumulative impact is significant: an iPhone that was worth £700 when new may be worth £300–£400 three years later in good condition, and £500–£600 after 18 months. Each passing September launch compounds the decline.

Older Models: Slower Decline, Lower Floor

Once an iPhone falls below a certain age, depreciation slows because it has found its floor value — mostly driven by the parts and refurbished entry-level market. An iPhone 11 might sit in the £70–£110 range for a couple of years before declining further. But this is still cash you could have in your pocket.

The Best Months to Sell Your iPhone

• July and August — The prime selling window for current-generation iPhones. Demand is still healthy and the September announcement cliff hasn’t hit yet. This is where you’ll find the highest trade-in values before the new model is unveiled.
• March–April — A secondary opportunity; values have stabilised after the post-Christmas dip and before mid-year. Good if you missed the summer window.
• Avoid October–November — This is the worst time to sell. New iPhone availability is high, the buzz is all about the new model, and demand for previous-generation devices has just experienced its sharpest drop.

Act Fast: Why Waiting Costs You Money

One of the most common mistakes people make is deciding to sell their iPhone but then leaving it in a drawer for months while they “think about it” or “get around to it”. Depreciation doesn’t pause because you haven’t made a decision. Every month you delay is money quietly evaporating.

Consider this: if your iPhone 15 Pro is worth £480 today and loses 2% of its value per month (a conservative estimate), you’ve lost nearly £100 in value over the next four months — simply from inaction. Meanwhile, the September announcement may be approaching.

Practical Steps to Maximise Your iPhone’s Trade-In Value

1. Set a reminder for mid-July — This prompts you to get quotes and sell before the September announcement
2. Get multiple quotes — Compare sellmyphones.co.uk/ with two or three other UK buyback services to verify you're getting the best price
3. Use the 14-day price lock — Accept your quote as soon as you’re happy with it; your price is then locked and won’t drop even if the market moves
4. Sort your backup and data wipe in advance — Having this ready means you can post immediately once your quote is accepted
5. Check battery health — If you’re planning to sell in a few months, avoid unnecessary overnight charging that degrades battery health

Want to know what your current iPhone is worth right now? Check our full iPhone value guide or head straight to our quote tool.