There are some excellent bargains to be had when buying a used Mac, but there are also some big bear-traps that could lose you both the Mac you thought you bought and the money you paid for it. This article suggests some precautions that could protect you from disaster when buying a used Mac.

My one and only golden rule is never to buy a used Mac without first seeing it in the flesh. That bargain a thousand miles away could turn out to have been stolen, and even if it’s genuine you could still end up with a useless Mac. I’ve never heard of anyone buying a house or car without seeing it for themselves, so I don’t see that a Mac should be any different. I suppose it’s feasible to go through the following checks over FaceTime or Zoom, but there are so many skilled con artists around that I simply wouldn’t risk it.

Once you arrive and see the Mac you’re about to purchase, work systematically through the following.

Provenance

Your first and most important question is whether this Mac is the seller’s to begin with. The best answer comes in the form of its original proof of purchase, giving its serial number. Check that matches the serial number given in Hardware Overview in System Information. If it doesn’t, then thank them politely and excuse yourself as quickly as you can. While you’re looking in that section, at the foot of that information you’ll see its Activation Lock Status: if that’s enabled, make a careful note, as you’ll need to get that disabled before you take your new Mac away.

Establishing provenance gets more complicated if that Mac has had more than one previous owner, but the current owner should ideally have a chain of bills of sale to reassure you. If they don’t, then that Mac may well have a murky past that could catch up with you.

Condition

Once you have confidence that you’re dealing with the real owner of the Mac, check it out as thoroughly as you can, without rushing or stripping it down to its logic board. A careful and undistracted visual examination is important, and gives clues through its general cleanliness as to how well it has been cared for.

It would be comforting to run hardware diagnostics just in case, although that’s not a particularly sensitive check for incipient problems. In ideal circumstances you’d want to check wear and any errors on its internal SSD using DriveDx or another SMART utility, but you’re unlikely to get the chance. If you have a friend who is a hardware technician, they could be a real boon to take along, just as you’d like to take a good mechanic when you go to check out a car.

AppleCare

If the current owner has AppleCare cover on that Mac, they should in most cases be able to transfer that with its sale. This requires them to sign into My Support for the agreement number and details, and with the original sales receipt for that Mac, to contact Apple Support and give them your details as the new owner. Apple explains this here, with useful onward links.

Haggle

I wish you success in agreeing the best price.

Activation Lock

The last hurdle in a successful purchase is the one most often forgotten, and the cause of much buyer remorse. It’s all the fault of Activation Lock and Find My Mac. These ensure that the owner’s Apple ID and password are required before that Mac can be used, erased, or Find My Mac disabled. In effect they make that Mac useless to anyone else until Activation Lock has been disabled.

Macs with T2 or Apple silicon chips running Catalina or later, where the user has 2FA on their Apple ID, are likely to be protected by Activation Lock. There is an additional requirement, depending on their architecture:

• Apple silicon Macs must have their security policy set to Full Security;
• Intel T2 Macs must have startup security set to Secure Boot, with booting from external drives disallowed.

Activation Lock is most commonly enabled when Find My Mac is turned on, and turning that off also disables Activation Lock. That requires entry of the current user’s Apple ID password, so must be done by the seller before they part with their Mac.

There are other ways to disable it:

• It’s automatically disabled when the owner runs Erase All Content and Settings, which is only available on T2 and Apple silicon models anyway.
• Activation lock can be disabled in the owner’s account at www[.]iCloud[.]com/find by removing that Mac from the list of All Devices there.
• If you have proof of purchase, you can request Activation Lock to be removed by Apple support, but that’s a last measure and not something you should ever choose.

Apple’s guidance is here.

Never take possession of someone else’s Mac while Activation Lock is active, as it will only cause you grief and trouble.

Handover

If everything is going well, you should be ready for the Mac to be handed over to your possession, accompanied by some written record of the sale. The conclusion is best seen as a mutual arrangement, as it gives the seller confidence that any data on that Mac is completely erased, and you the confidence that you’re about to gain a Mac you can use.

If it’s an Intel Mac, confirm with one another that it starts up without requiring a firmware password. Then, if it has a T2 or Apple silicon chip, use its Erase All Content and Settings together to ensure that all its old files are made unreadable, and to be certain that Find My Mac and Activation Lock are disabled. Sadly, erasing older Intel Macs without T2 chips is a slower and more complicated process.