The inner display
The large folding screen is the main display on a Fold and the only full-size screen on a Flip, so its condition carries a lot of weight. The inspection looks for dead pixels, lines, discoloured or bright patches, areas where touch doesn't respond, and any damage along the fold. A fault on the inner screen usually counts for more than light scuffs on the frame, because it affects how the phone is used every day. If part of the inner display has stopped working, say so on WhatsApp. A damaged foldable can still be sold, but the estimate should reflect the damage from the start.
The crease: normal versus damage
Every Galaxy foldable has a crease where the display folds. Samsung describes the crease as a normal feature rather than a defect, a result of the foldable design and the Ultra Thin Glass it uses, and says it can't be completely eliminated. Samsung also notes that on the Z Flip5 and Z Fold5, the crease may look slightly larger than on earlier models because of the newer hinge. So a visible crease on its own is expected. What matters is anything beyond it, such as a bump or dent that has formed at the fold, lines or dead pixels running along it, or the protector bubbling or lifting there.
The factory screen protector
Galaxy Z Fold and Z Flip phones come with a protective film already fitted to the main screen, made to cope with folding. Samsung recommends that you don't remove it yourself: its guidance says removing it or fitting a non-official film may cause touch problems or screen damage, and that replacement should be done at a Samsung service centre. So even if the film has started bubbling or peeling at the edges, don't pull it off to make the phone look tidier before selling. Mention its condition on WhatsApp instead. A lifting protector is simply part of the condition picture, while a screen damaged during removal is a far bigger problem.
Hinge feel and gaps
The hinge is checked by opening and closing the phone and holding it at different angles. It should move smoothly, without grinding, creaking or looseness, and hold its position when partly open, as it does in Flex mode. Debris caught near the hinge and dents on the hinge cover are noted too. Gaps depend on the generation: Samsung says the hinge on the Z Flip5 and Z Fold5 closes with minimal to no gap, while earlier models close with a visible gap by design. So the inspection compares your phone with how its own model is meant to close, rather than expecting every generation to look the same.
The cover screen
The outer screen matters too. On a Fold it's a phone-style display you use while the device is closed; on recent Flip models it's the FlexWindow, which Samsung made edge-to-edge on the Z Flip7. The cover screen is checked for cracks, scratches, dead areas and touch response, just like any other phone display. A crack here lowers the offer but doesn't rule out a sale. Because a Flip spends most of its time closed, its cover screen and the glass around the rear cameras can take more knocks than the inner display, so look at them closely before you describe the condition on WhatsApp.
Frame, back and battery
Foldables have plenty of edges and corners, so dents on the frame or around the hinge, scratches on the back and cracked back glass all count toward body condition. The battery is assessed just as it would be on any other Galaxy. Signs worth mentioning include noticeably faster drain, unexpected shutdowns or any sign of swelling. Samsung's Members app has a phone diagnostics feature that reports battery status, which gives you something concrete to share. If you've had the battery or a screen replaced, say whether it was done at a Samsung service centre or elsewhere, since original versus replacement parts is part of the inspection.
S Pen support depends on the generation
S Pen support only applies to some Fold models. Samsung says the S Pen Fold Edition works with the Galaxy Z Fold3, Z Fold4, Z Fold5 and Z Fold6, and it was sold separately rather than included in the box. The Galaxy Z Fold7 dropped S Pen support to make the phone thinner, and the Z Fold8 models haven't brought it back. No Galaxy Z Flip has ever supported the S Pen. If you're selling a Z Fold3 to Z Fold6 and still have an S Pen Fold Edition, or a Samsung case with a pen holder, mention it on WhatsApp so it can be considered along with any other accessories.
Lock status and what to send for an estimate
Lock status works the same as on any Galaxy. A Fold or Flip still signed in to a Google account is under Factory Reset Protection and can't be bought, so remove your Google account, sign out of your Samsung account and turn off Find My Mobile before you reset. For an estimate, send the exact model (for example Z Fold7, Z Flip7 or Z Flip7 FE), the storage, the condition of both screens, whether the factory protector is bubbling or peeling, how the hinge feels, battery status if you know it, and any repairs. The final offer is confirmed after inspection, with an explanation of what affected it.