HP Plus comes with a huge catch
If you buy some HP printers, you’re given a limited-time chance to get six months of free ink, a better warranty, and even plant a tree in your name. You must sign up for HP Plus with seven days of printer connection, and HP will happily remind you of this deadline constantly, until you sign up or your time runs out. If you sign up, you actually get free ink for six months, but you also agree to a firmware update in the fine print. Once you’re a member of HP Plus, your printer will never accept ink that doesn’t come directly from HP. Sounds inconvenient but not terrible, unless you remember everything HP has done with its printers.
HP has been in the news quite a bit, like when it was revealed that the printer was using more ink than it needed to. In a way, it didn’t matter because HP also included an artificial end date on the life of the ink cartridges. Once that time comes, no matter how much ink is left in the cartridge, your printer would claim it was empty. They also tried blocking official HP ink cartridges from a different region than where the printer was purchased from working, plus an update that blocked all third-party ink cartridges. Legally speaking, most of these attempts failed.
However, by signing up for HP Plus you’ve expressly agreed to limit the cartridges you use, so you’ll be out of luck. If you were hoping that canceling HP Plus would unlock your printer, apparently the firmware update is irreversible; you will need to buy a new printer.