The short answer: Do not buy an iPhone that remains Activation Locked. Confirm it can be activated, check carrier compatibility, inspect battery and repair information, and test essential functions before completing the purchase.
A clean screen and a low price are not enough. A phone can look excellent while being unusable with your account or carrier. Treat setup and ownership-related checks as the first step, not something to sort out after the seller leaves.
What is Activation Lock, and why does it matter?
Activation Lock is designed to prevent someone other than the owner from using the device. Apple's preowned-iPhone guide says not to buy an iPhone with Activation Lock enabled.
If the device says "iPhone Locked to Owner," the seller must properly remove the lock using their own account. Do not accept a promise to send a password later or pay for an unofficial bypass.
A Hello screen indicates the phone was erased, but it still needs to be set up and activated for a meaningful check. Do not mistake a photograph of that screen for proof you can use the device.
Is carrier lock the same as Activation Lock?
No. Carrier restrictions concern the mobile network the phone can use. Apple explains that "No SIM restrictions" next to Carrier Lock in Settings indicates an unlocked iPhone. Menu wording can vary with software.
Before buying, ask your intended carrier to confirm that the exact model and device identifier are eligible for service. Model region, SIM or eSIM support, and carrier requirements can matter. Carrier unlocking does not by itself prove ownership or guarantee that every future account issue is impossible.
How do I check used-iPhone battery health?
Look in the Battery settings for available health information and service messages. Apple notes that battery-health information may not be available for unknown or nongenuine batteries.
Do not choose an arbitrary percentage as the only buying rule. Consider the age, expected daily use, performance warnings, and a current battery-service quote. A discounted phone requiring immediate work may cost more than a better-maintained alternative.
If the device will not charge, becomes unusually hot, or appears damaged, stop the purchase and seek professional advice. Do not try to open a battery during a marketplace meeting.
Can I tell whether parts were replaced?
On supported models and software, Settings, General, About may show Parts and Service History. Apple explains that available information depends on the model, software, and replaced component.
Read any warnings carefully and ask for repair documentation. A missing history section is not proof that every component is original. "Refurbished" also does not describe one universal standard; ask exactly what the seller tested and what warranty or return terms are included.
What should I test in person?
- Display brightness, touch response, and visible damage.
- Buttons, speakers, and microphone recording.
- Front and rear cameras, including focus and video playback.
- Wi-Fi and the supported charging connection.
- Basic setup and the absence of an unresolved owner lock.
Ask the seller to remove the case so you can inspect the edges and back. Allow time for tests rather than agreeing to a handoff in which the phone stays powered off.
Is buying online different from buying locally?
For a shipped purchase, read the return policy before ordering. Save the description and inspect the device promptly after delivery. The FTC's marketplace advice emphasizes checking buyer protections and payment rules.
For a local purchase, arrange a suitable public meeting and do not let inspection require sharing your passwords or security codes. If you decide not to buy after using personal information during setup, remove that information safely before returning the device.
Bottom line: A usable, verifiable phone is worth more than a bargain with unresolved locks. Compare electronics listings only after deciding which model and carrier requirements you need.
Sources and fact-check date
Reviewed October 21, 2026 against Apple's preowned-iPhone instructions and FTC marketplace guidance. Features vary by model and software; this checklist does not certify a device's ownership or future reliability.