Apple is a company that knows how much their customers love novelty. Accordingly, fireworks of new Macs are regularly set off for the Apple keynote - or not. If you want a new Mac or have already bought it, you can often sell the old one used at a very good price. Since Macs are comparatively rare, the used prices are high and it is nonsense to keep the old device in the closet and let it become obsolete there.
Reset Mac to factory settings: Here's how
Unfortunately, unlike Windows or iOS, macOS doesn't offer a simple, quick way to reset your Mac to factory settings with just a few clicks. Simple formatting is also not useful, and sometimes even extremely problematic . A little preparatory work is required here, also due to the deep iCloud link. We'll help you reset your Mac and get it ready for sale.
Package and sell your Mac
The Mac is now completely factory reset and ready for sale. You can now clean and pack the device - or take photos for Ebay and Co. The buyer receives the Mac in the same software condition as if he had purchased a new device from Apple. The only difference is that he may still have to install the newer macOS versions, but this should be in the interests of the buyer..
By the way: Simply resetting the same macOS version via normal system rescue (without Internet recovery) is not recommended: If the buyer has not purchased the appropriate macOS version in the AppStore, he will not be able to activate it. So always use the Internet recovery or the supplied DVDs, otherwise problems can arise.