Selling or trading in your Mac is exciting — new computer, some money back, fresh start. But it’s also one of the easiest ways to accidentally give someone access to your entire digital life.

I’ve walked dozens of clients through this process over the years. Done right, it takes about 30–60 minutes. Done wrong, you could be handing over your iCloud account, your saved passwords, your photos, and your banking apps to a stranger.

Here’s exactly what to do, in order.

1. Back Everything Up First (Non-Negotiable)

Before you do anything else — before you sign in anywhere to deauthorize, before you touch a single setting — make a full backup.

Time Machine to an external drive is the standard move. If you haven’t been doing regular backups, now is the time. Plug in a drive, open Time Machine in System Settings, and let it run a full backup.

I also strongly recommend having an offsite backup — meaning a copy that isn’t sitting right next to your computer. Backblaze is what I recommend to almost every client. It runs quietly in the background and keeps a continuous backup of your entire Mac in the cloud for about $9/month. If you don’t have it, this is a good moment to set it up on your new machine.

Once you have a verified backup, you’re ready to move forward.

2. Transfer or Note Down What You Need

Before wiping anything, take stock of what lives on this machine that you’ll want on the next one:

This step catches the things people call me about two days after they sold their old Mac.

3. Sign Out of iCloud

This is the most important security step. If you skip this, your Apple ID stays linked to the machine, and whoever buys it may be able to see your iCloud data or activation-lock you out of a future device.

How to do it:

Signing out of iCloud also automatically disables Find My on that machine, which the buyer will need for activation.

4. Deauthorize iTunes / Music

If you’ve purchased music, movies, or apps through Apple’s ecosystem, your Mac counts as one of your five authorized computers.

If you skip this, you won’t lose anything — but you’ll burn one of your five authorizations until you get around to it.

5. Sign Out of Other Apps

Any app that uses your account should be signed out before you erase the machine. Work through this list:

6. Erase the Mac and Reinstall macOS

This is the clean wipe. The process differs slightly depending on whether you have an Apple Silicon Mac (M1, M2, M3, M4) or an older Intel Mac, but the goal is the same: factory reset.

For Apple Silicon Macs (2020 and later):

For Intel Macs:

When it’s done, you’ll see the setup screen — the same thing a brand new Mac shows. Stop there. Don’t set it up as yourself. Let the buyer do that.

7. Clean It Up Physically

A clean Mac sells faster and for more money. Wipe down the screen with a slightly damp microfiber cloth, clean the keyboard, and remove any stickers if you can do so without leaving residue.

Include the original power adapter if you have it. It adds value and makes the whole transaction feel more professional.

One More Thing: If You’re Migrating to a New Mac

If you’re not just selling — you’re also setting up a new machine — there’s a specific order that makes migration much smoother. I’ll cover that in a separate post, but the short version is: do the Migration Assistant step before you erase the old Mac, not after.

If you’d rather have someone walk you through the whole thing, that’s exactly the kind of session I do remotely or on-site. Reach out and we’ll get it scheduled.