What price for a used iPhone in Switzerland?

A scratched but healthy phone sells better than a spotless one whose battery is worn out.

The battery, the first figure to ask for

iOS shows the battery's maximum capacity under “Settings → Battery → Battery Health”. It is a percentage, and it is the most useful piece of information in the whole listing.

Ask for a screenshot of that screen. A seller who won't provide one is telling you something.

Below a certain threshold, iOS itself displays a “service recommended” message: at that point, factor the cost of a battery replacement into your offer.

Locks: the check that saves you from the worst

Two different locks, and both make a phone unusable:

• iCloud Activation Lock. If the seller's account has not been removed, the device is a brick. Insist that the phone is fully reset and removed from the account before you pay, and check that the welcome screen does ask you to set up a new account.
• Network lock or IMEI block. A phone reported stolen or unpaid can be blocked on the network. Ask for the IMEI — it appears when you dial *#06# — and for the purchase receipt.

An iPhone with no receipt, priced well below the market, with a seller in a hurry: those are exactly the three warning signs together.

Capacity, more than the model

The price gap between the 128 GB and 512 GB versions of the same model is often bigger than the gap between two successive generations. Put the capacity in the title of the listing, not in the description.

What matters less than you might think

• The colour. It makes almost no difference.
• The original box. Nice to have, marginal.
• Micro-scratches on the screen. A buyer who fits a screen protector couldn't care less.

What matters more than you might think

• A screen or battery replaced outside the authorised network. iOS shows it in the device information, and it makes the value drop.
• The number of years of updates left. A model nearing the end of software support sells for noticeably less, and informed buyers know it.

Selling at the right time

The value of an iPhone falls in steps, in time with Apple's announcements — not continuously. Selling just before a new generation is announced is better than selling three weeks after.