When to Sell Your iPhone in the UK (Before iPhone 18)

Your iPhone Is Quietly Losing Hundreds of Pounds a Year#

Here is the uncomfortable truth about the phone in your drawer: it is a depreciating asset, and it depreciates on a schedule.

We buy iPhones every day, so we can see the whole ladder at once. At the time of writing (8 September 2026), a pristine iPhone 17 Pro Max is worth up to £905. The generation before it, the 16 Pro Max, tops out at £711. The 15 Pro Max sits at £511. That is roughly £200 gone with each step back in time — not spread evenly across the months, but banked in one lump each time a newer model arrives and pushes the old one down the pecking order.

The verdict, up front: if you own an iPhone you are not using, the single most valuable thing you can do is sell it before the iPhone 18 trade-in wave lands. Apple's keynote was Wednesday 9 September 2026, and the new iPhone 18 Pro and Pro Max go on sale on Friday 18 September. Get a quote now, and TechLoop's 14-day price lock holds today's figure for you even if you post the phone after your new one arrives. Waiting past the launch is where the money leaks out.

Here is the generational ladder — the same numbers we quote customers, top condition, at the time of writing (8 September 2026).

Read it top to bottom and the shape of iPhone depreciation jumps out: each of the two most recent steps is worth about £200, and the curve flattens as the phone ages. A one-generation-old Pro Max has already shed close to £200, a two-generation-old one about £400. Further down, a four-generation-old 13 Pro Max still fetches up to £331 — £180 below the 15 Pro Max despite being two generations older — because it has almost finished falling. Every one of those figures is real buyback money, not an eBay best-case or a trade-in voucher.

These are illustrative prices at the time of writing (8 September 2026), and they move over time as new models launch and demand shifts. Storage matters too — larger capacities are worth a little more. For your exact figure, see what your iPhone is worth in about 30 to 60 seconds.

What the Numbers Actually Show#

It is worth slowing down on that table, because the pattern in it is the whole argument.

Depreciation is per-generation, not per-month. People tend to imagine their phone losing a steady few pounds every month, like a car ticking down the odometer. The data does not really work that way. A phone holds fairly firm through most of a model year, then takes its biggest single hit when the next iPhone is announced and it is suddenly "last year's model" in buyers' minds. That is why we frame this per-generation rather than quoting a precise monthly figure we could not honestly stand behind. The loss is real and predictable; it just arrives in steps, and the steps line up with September.

The newest phones lose the most in pounds. The gap from the iPhone 17 Pro Max to the 16 Pro Max is £194. From the 16 to the 15, it is £200. Then it flattens: the 13 Pro Max, two generations further back, sits £180 below the 15 — roughly £90 a generation rather than £200. If you own a recent, high-value iPhone, you are sitting on the steepest part of the curve — which is exactly the position where waiting costs you the most. Someone with an older iPhone 13 Pro Max has far less left to lose.

The standard line follows the same shape, smaller in pounds. You do not need a Pro Max for this to apply.

The pounds are smaller and the steps are uneven — the 17 and the 16 sit close together today (a £19 step), while the 16 to the 15 is a £120 step. On a phone gathering dust, that is money you are choosing to leave on the table.

This is the kind of data almost nobody in the buyback niche publishes, so treat it as a genuine benchmark rather than marketing. It is a snapshot of one moment — 8 September 2026 — from one buyer's live prices. It will drift. But the shape of it, the per-generation step-down clustered around each launch, is what the used market shows every September.

From "Up To" to Your Actual Quote#

Every figure above is the pristine price — a phone that looks and works like new. Most phones are not pristine, and that is completely fine; we grade honestly and pay accordingly. As a rough guide, Good condition comes in around 85 per cent of the pristine figure, Fair around 70 per cent, and a cracked or faulty phone around a quarter. Here is how that scales on the top three Pro Max models.

A couple of honest caveats. These are illustrations, not a promise to the pound — the exact multiplier depends on the specific marks, battery health and storage, and it is set when we inspect the device, not guessed from a photo. And even a cracked, water-damaged or non-working iPhone has a real Poor-grade price; we buy those too, including phones that will not switch on, so long as the phone is not iCloud-locked or blacklisted. If your phone is in between grades, the safest thing is to check your iPhone 15 Pro Max value — or whichever model you own — against a live quote rather than eyeballing it from this table.

Why iPhones Drop When the Next Model Launches#

The keynote effect is the single biggest lever on your phone's resale value, and it is worth understanding why it bites so hard.

Supply and demand move against you at the same moment. When Apple announces a new iPhone, two things happen in the same week. First, buyers who were about to pick up a used iPhone 17 pause — they want to see the new model, its features and its price before committing. Demand cools. Second, thousands of other owners have exactly your idea and rush to sell their old phones to fund the upgrade. Supply spikes. More phones chasing fewer buyers can only push prices one way.

It starts at the announcement, not the shipping date. This catches people out. The value does not wait politely until the iPhone 18 is on shelves. The moment it is announced on stage, your iPhone 17 becomes "the old one," and buyback prices begin drifting down within days. By the time you have watched the reviews, thought about it, and finally got round to selling, a good slice of the drop has already happened.

It is reliable in direction, if not to the exact pound. We would not claim your specific phone will fall by an exact amount on an exact date — that would be overclaiming, and the real world is messier than that. What we can say is that the direction is dependable: the used market shows this every September, with prices around a launch softening rather than firming up. Betting against that pattern rarely pays off for a seller.

Put those three together and the timing conclusion writes itself. The window where your current iPhone is usually worth the most is the stretch before the September keynote. After it, you are selling into a falling market alongside everyone else.

The Best Time to Sell: Before the September Keynote#

So here is the concrete recommendation for 2026: aim to have your iPhone sold, or at least quoted and locked, before the iPhone 18 trade-in wave lands. Apple's keynote was Wednesday 9 September; pre-orders open on Saturday 12 September at 1 p.m. UK time, with phones on sale from Friday 18 September. The heaviest trade-in supply follows in the weeks after that.

If you are ready to part with the phone now, there is nothing to wait for. But most people are not quite ready — they want to back up photos, buy the replacement first, or simply get round to it. That is exactly the gap the price lock is built for.

How the 14-day lock protects you. When you get an online quote, TechLoop holds that price for 14 days. Get your quote this week and the figure is held to the end of September — straight through pre-orders and the first deliveries. If market prices soften now that Apple has taken the stage, it does not matter: your locked quote still stands when the phone arrives and is inspected. You have effectively frozen today's higher price while you sort out the practicalities.

If your upgrade arrives as a second phone you do not need — a sealed iPhone 18 Pro from a carrier deal — that is the other way to turn this launch into cash. A sealed, unopened phone grades as Pristine; see selling your iPhone upgrade for cash.

How the flow works, start to finish:

1. Get an instant quote at /sell — around 30 to 60 seconds, no account needed. That starts your 14-day lock.
2. Accept it, and we email a free Royal Mail tracked postage label. The label expires after 7 days (separate from the 14-day quote validity), so print and post within a week.
3. Factory-reset the phone and drop it in the post. Every device we receive also gets a GDPR-compliant data wipe, but reset it yourself first anyway.
4. Once it arrives and passes inspection, you are paid the same working day by bank transfer. Prefer cash and near Wiltshire? Our Swindon walk-in store pays on the spot.
5. If we ever revise the offer after inspection and you are not happy, decline it and we return the phone free. No obligation.

That is the entire mechanism for beating the keynote drop: lock now, post when you are ready, get paid fast. If you own a current flagship, this matters most of all — sell your iPhone 17 Pro Max while it is still near the top of the ladder, because it has the furthest to fall. Not sure the upgrade is worth it? iPhone 18 Pro Max vs iPhone 17 Pro Max weighs it up.

Eligibility and the Small Print Worth Knowing#

Before you count the money, three things worth knowing so there are no surprises at inspection.

It does not have to power on. Cracked, water-damaged, faulty and completely dead iPhones are all welcome at a Poor-grade price. A phone that will not switch on grades as Poor, and we still buy it — the two checks below are the ones that actually matter.

No account lock. Turn off Find My and sign out of iCloud before you post. An iCloud-locked iPhone cannot be resold or processed, so this is the one step that genuinely holds up a payout. On Android it is the equivalent Google or Samsung account lock.

Not blacklisted. A phone reported lost or stolen, or blocked by a network, cannot be bought — by us or by anyone legitimate. If yours is clean and simply old, you are fine.

None of this is unusual, and none of it is a trap. It is the same short checklist any honest buyer runs. Clear those two and the process is genuinely as simple as it sounds.

Common Mistakes When Timing an iPhone Sale#

Waiting to see the new iPhone before selling the old one. This is the classic, and it is backwards. Now that the iPhone 18 Pro has been unveiled, the drop in your current phone's value has already started. If you were always going to sell, the value-maximising move is to sell — or lock a quote — before the trade-in wave lands, not after you have admired the new one.

Confusing "I'll sell later" with "it'll hold its value." These are not the same. Deciding to sell in a few months is fine; assuming the price will still be there is the error. On a recent Pro Max, "later" can quite literally mean hundreds of pounds less. If you want the flexibility of later with the price of now, that is what the 14-day lock gives you.

Over-grading your own phone. Optimism is expensive here. A phone you consider "basically mint" with a few micro-scratches may grade as Good, not Pristine. We grade on inspection and explain any difference, and you can always decline a revised offer and get the phone back free — but you will save yourself the back-and-forth by being honest with the condition from the start.

Assuming a broken iPhone is worthless. It is not. A cracked or faulty phone still has a real Poor-grade price — often a meaningful two- or three-figure sum on a recent model — and that beats a drawer every time.

Letting the postage label lapse. The quote is locked for 14 days, but the Royal Mail label expires after 7. Accept, then actually post within the week so you do not have to regenerate anything.

Selling to the first tab you open. Prices vary across services. Check a couple. If you want a fast, transparent starting point, check what your iPhone is worth and compare from there.

The Bottom Line#

Your iPhone is unlikely ever to be worth more than it is today. That is not a sales line — it is the shape the numbers show. A pristine iPhone 17 Pro Max is £905 today; the generation behind it, the 16 Pro Max, is a £711 phone, and the 15 Pro Max a £511 one. That is the size of one generational step. The value does not trickle away evenly; it drops in steps, and the biggest step lands with the September launch.

You have two honest choices. Sell before the iPhone 18 trade-in wave lands and capture today's price, or wait and hand a chunk of it to depreciation. If you are not using the phone, only one of those makes sense.

The practical move takes under a minute: get an instant quote on TechLoop to see your exact figure, and the 14-day lock holds it for you straight through the keynote window. Postage is free, payment lands the same working day the phone passes inspection, and if the number does not work for you, you have lost nothing but 60 seconds. Own a current flagship? Start with sell your iPhone 16 Pro Max or sell your iPhone 14 Pro Max — then turn the phone in your drawer into money before the market decides it is worth less.

Prices in this article are illustrative real buyback figures checked on 8 September 2026 and are the pristine "up to" values before condition adjustments. All prices change over time as new models launch and demand shifts. TechLoop quotes are live and lock for 14 days — check a live quote at /sell for current pricing on your exact model, storage and condition.

TechLoop is an independent Swindon business. We are not affiliated with Apple.