A chip decides whether your ink counts, and HP can flip that switch after the salehttps://unsplash.com/photos/5AoOejjRUrAHP calls it Dynamic Security. It's an authentication system, introduced in 2016, that checks whether an installed cartridge carries an HP-made security chip. HP has pushed it through firmware updates to machines people already owned, sometimes years after purchase, according to court filings in the consolidated federal case In re HP Printer Firmware Update Litigation. A November 2020 firmware push reactivated Dynamic Security on printers where it had gone dormant, triggering a fresh US class action. If you only ever buy genuine HP cartridges, Dynamic Security will never be a problem for you.